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Never trust her at any time, when the calm sea shows her alluring smile.
—De Rerum Natura Titus Lucretius Cams 99-55 B.C.
It happened during the Cutty Sark Tall Ships Race from Puerto Rico to Halifax, Nova Scotia. At 0400 eastern daylight time (EDT) (0800 Greenwich mean time [GMT]) on Sunday, 3 June 1984, less than 13 hours into the second leg of the race from Bermuda to Halifax, the 117-foot barque Marques sank in less than 60 seconds in heavy weather about 80 nautical miles north northeast of Bermuda.
Only nine of the 28 crewmembers survived. Among those who went down with the ship were her skipper Stuart Finlay, his wife, and 15-month-old baby.
What happened?
Stuart Finlay and his ship were riding the crest of the wave on a north northeasterly course. And there was good reason for Finlay’s high. In tough international competition, he and the Marques had won the Puerto Rico-to- Bermuda leg of the race to Halifax.
And he was overjoyed and confident that he could pull off a victory on the leg from Bermuda to Halifax.
Then how could a disaster like this occur? And so quickly?
Was Stuart Finlay a sufficiently knowledgeable and seasoned skipper for the task?
After completing his studies at Boston University, Finlay was commissioned into the Navy through the Naval Reserve Officer Training Corps and assigned to the U. S. Naval Academy. He was assistant sailing officer in 1966 and chief sailing officer the following two years, teaching competitive and recreational sailing.
Following service in the Navy, Finlay taught at various schools in Massachusetts. About seven years ago, he gave up his teaching career to pursue his greatest love, sailing. First he operated charter boats out of Antigua, the West Indies, then progressed to the 117-foot square-rigged Marques and the 125-foot brigantine Ciudad de Inca.
The Marques had been recently refitted in England, and Finlay sailed her home. The voyage was extremely rough and dangerous. The ship encountered seven gales, but Finlay brought her through safely. He had extensive experience as a sailor and was considered an extraordinary seaman by his colleagues. One cannot fault his knowledge or experience.
Was the Marques seaworthy?
Although the ship was built in Spain 67 years ago, she had been completely rebuilt in 1971 when she was purchased as a hulk by the South China Clipper Society of England.
The Marques was rated at 82 gross registered tons, displaced 180 tons, had a beam of 24 feet, six inches, and drew ten feet, six inches. The ship had been issued a U.K. Department of Transport Load Line (Exemption) Certificate of Seaworthiness in June 1983. Experts considered the ship to be well found. So it would seem that the ship’s integrity should not be at issue.
Should the second leg of the Cutty Sark Tall Ships Race from Bermuda to Halifax have been postponed because of the weather?
On Friday, 1 June 1984, Bermuda was buffeted by severe, gusty southerly winds and heavy rain showers. But by the early morning hours of 2 June, weather conditions had begun to moderate. The decision was made to go ahead with the race as scheduled— starting time 1400 EDT (1800 GMT)- Bermuda was experiencing partly cloudy skies with low, middle, and high clouds; a temperature of 79° Fah| enheit; barometric pressure 1013.2 n" libars (29.92 inches of mercury) and falling very slowly; unlimited visibil'D’ and southerly winds of 15 knots. Winds over the southern course of the race in the vicinity of Bermuda wef° forecast to be 15 to 20 knots.
“We would not have sent the fl°et off if there had been any question about the weather,” stated Oliver Pe,rl_ berton, the U.K. Sail Training Ass°cia tion (UKSTA) spokesman. But the forecast proved wrong. v
After the 39 tall ships got under ^ on the second leg en route to Halifa*’ the wind increased to a steady 30 pluS knots with gusts to 45 knots. Wave heights increased rapidly to 20 feet-
When asked for his opinion, Kirk Cooper, the former commodore of 1,1 Royal Bermuda Yacht Club, said that he concurred with the UKSTA decis'0 to start the race.
“We would have started in those conditions as long as the forecast vvaS^ not for worsening conditions,” he sa' “‘[T]he weather for New York and ^ East Coast was quite bright. It wasn as if there was a deceptive area of 10 pressure that could have affected the course.” .
So, on the basis of the weather in formation and forecasts made avail2 ,
not criticize the officials for starting ^ race. Unfortunately, the forecast was bust. . e
What really happened to preciplta the tragedy? [j.
>
Did the racing fleet en route to fax encounter a meteorological ^ “bomb,” a term coined by Profess0
• Sanders and J. R. Gyakum of the Massachusetts Institute of Technology, 'refers to maritime surface cyclones aat develop, or “deepen,” explosively when the central pressure average falls least one millibar per hour for 24 hours.
Was such a “bomb” responsible for '•'e Marques tragedy?
To look for an answer, we must go ack a week before the start of the
utty Sark Tall Ships Race’s second
'eg.
Early in the week of 27 May 1984, j* developing storm caused destructive ash floods in and around Tulsa, Okla- 0,t'a. This storm, with its attendant c°ld front and a secondary trough of low pressure, became the culprit responsible for a disaster to occur a week later north of Bermuda on Sunday morning, 3 June 1984.
The earliest indication of potential danger to the Cutty Sark Tall Ships Race participants came from four vacationing “pleasure sailors” on board the 30-foot fiberglass sloop Mirebel late Thursday night, 31 May 1984.
Two days earlier, at midnight Tuesday, 29 May, Dr. William M. Stone, M.D., of Alexandria, Virginia, and owner of the Mirebel; Edward Pan- talone, an insurance agent from Fairfax County, Virginia; along with lawyers Eugene Ferretti and Norman Morse set sail from Solomons Island, Maryland, on board the Mirebel for a leisurely cruise to Bermuda.
The cruise was pleasant and uneventful until Thursday, 31 May. As the intensifying low pressure system from Tulsa, Oklahoma, traveled eastward at 16 knots gradually, closing in with Mirebel now east of Cape Hatteras, North Carolina, the weather and sea
Bermuda’s weather at this time
with
southeasterly winds of 20 knots
sure
Figure 4 is the GOES EAST gf tionary weather satellite’s view
situation. Bermuda is at the tip of 1 black arrow. Note the intensity of 1 cold front approaching Bermuda By 2000 EDT Friday, 1 June
Figure 1
Figure 2
Figure 3
conditions deteriorated rapidly. Strong winds and increasing seas forced the four vacationers to furl the sloop’s sails.
“The weather fooled everybody,” Pantalone is reported to have said.
“We took every reasonable precaution, but the boat was out of control because of the winds and seas. It just got worse and worse Thursday night. We hadn’t eaten anything for 24 hours. All the hatches leaked. We became weakened. The bunks and our clothes were all wet.”
By 2000 EDT Thursday, 31 May (0000 GMT, Friday, 1 June), the intense low-pressure system from Tulsa had moved to a position near latitude 37.2° north-longitude 71.1° west, approximately 145 nautical miles west northwest of the Mirebel, as shown in Figure 1. At this time, the low had a central pressure of 1,004 millibars (29.65 inches of mercury) and was moving north northeast at 23 knots opening with the Mirebel. The huge frontal system associated with the low, however, extended all the way from Labrador southward to central Cuba.
The strong cold front to the south of the low was moving eastward toward the Mirebel at 8.5 knots. As the front approached Mirebel, southerly winds increased rapidly to between 35 and 40 knots with gusts to 50 knots. Rapidly increasing seas were running about ten to 15 feet from a generally southerly direction. But the seas were starting to become confused with northwesterly waves and swells.
At this time, the weather in Bermuda was beautiful: partly cloudy skies with some low and middle clouds, temperature 74°, visibility unlimited, winds from the southeast at ten knots, and barometric pressure 1,018.7 millibars (30.08 inches). The cold front was 400 nautical miles to the northwest.
By 0600 EDT (1000 GMT) on Friday, 1 June, the four vacationing “sailors” on board the Mirebel, considering themselves in grave danger, began radioing Mayday calls. At this time, Mirebel was approximately 55 nautical miles east of the cold front which was still moving eastward at 8.5 knots. Southerly winds were now blowing at 40 to 50 knots with some gusts to 60 knots. Confused seas were running as high as 20 feet.
Mayday calls from the Mirebel were first heard at 1120 EDT (1520 GMT) on Friday, 1 June. Picking up these distress signals, the Omoa, a Honduran-registered cargo vessel on her way to Savannah, Georgia, changed course and headed for the Mirebel. The Omoa reached the sloop in distress at 1230 EDT (1630 GMT), approximately 360 nautical miles east of Cape Hatteras.
It took more than four hours to transfer the four Mirebel sailors from their sloop to the Omoa in life rings because both vessels were pitching sharply in the heavy seas.
The four rescued sailors, sustaining only minor injuries and happy to be alive, flew home from Savannah, where the Omoa had put them ashore.
Figure 2 shows the surface weather map for 0800 EDT (1200 GMT) Friday, 1 June, four and a half hours before the rescue of the Mirebel sailors. The low-pressure system at this time was located with coordinates near 40.6° north-69.7° west and was moving north northeast at 17 knots opening with the Mirebel. The central pressure had fallen one millibar to 1,003 millibars (29.62 inches). The cold front was now a mere 40 nautical miles to the west of the sloop and was moving eastward at 15 knots.
At this time, the weather in Bermuda was overcast with breaks; with low, middle, and high clouds; winds southeasterly at 20 knots; temperature 75°; and barometric pressure 1,016.1 millibars (30.01 inches). The cold front waS now 280 nautical miles to the west ot the island.
At approximately 1030 EDT (1430 GMT), two and a half hours after the weather conditions depicted in Figure 2, the cold front passed over the Mirebel. Gale force winds shifting ruptly from south southwest to northwest and confused high seas accompa nied the frontal passage.
Figure 3 shows the surface weather situation at 1400 EDT (1800 GMT) °n Friday, 1 June, one-and-a-half hours after the rescue of the Mirebel sailors by the crew of the Omoa. The low- pressure system was now centered ne 41.1° north-69.0° west and was revers ing course traveling south southeaste at 18 knots. Central pressure of the had fallen to 1,001 millibars (29.56 inches). The cold front was approximately 165 nautical miles to the nod > west of Bermuda and was approachin- the island at 19 knots.
overcast with low and middle clouds- visibility restricted by haze, south
higher gusts, temperature 76°, pres: 1,013.1 millibars (29.92 inches) and falling rapidly.
What many meteorologists failed 10 take note of on the 1800 GMT surfac weather map on Friday, 1 June, WaS. g the early clue of potential trouble^ first signs of the development of a s ondary trough of low pressure, fr°n1^ the center of a low front located to southeast of Cape Cod and extending west southwestward to the Delaware ^ Maryland-Virginia peninsula and in across the state of Virginia.
- 2eosta of the
the
West of Bermuda, as shown in Fig-
to 1 rr o j
“ermuda had only a few scattered v> middle, and high clouds; winds re from the west southwest at 20
. °ts; visibility was excellent; the tem- rature was 73°; and the barometric (2gSSUre lla(J risen to 1,013.1 millibars ^ 92 inches). It appeared that things knj booking up” for the Bermuda- lalifax leg of the Cutty Sark Tall
Figure 5
Figure 6
Figure 8
^MT Saturday, 2 June), the cold front ^ located only 80 nautical miles to
Ure 5. The low-pressure center (central Pressure having fallen to 997 millibars "”•44 inches]) was now located at north-68.0° west and moving tl0rth northwest at 13 knots. The devel- °Ping secondary trough of low pressUre—still unnoticed, underestimated in Potential, or ignored by many meteor- logists—had swept southeastward at ■t knots and was now passing through J?e Cape Hatteras area and both the Molinas.
The weather in Bermuda at this time Was overcast with heavy rain showers ajtd distant lightning, low and middle j’Ouds, winds from the south at 35 Kn°ts and very gusty, temperature 72°, and pressure 1,009.1 millibars (29.80 jnches)—a drop of four millibars in the ast six hours.
At 0800 EDT (1200 GMT) on Satur- .ay> 2 June, the surface weather situa- °n was as shown in Figure 6. The 01d front was now located 230 nauti- j niiles to the east of Bermuda, hav- 8 passed over the island approxi- ately eight-and-a-half hours earlier raveling at 27 knots.
' he low pressure system, with a .er*tral pressure of 990 millibars (29.24 Pches), was now located at 40.7° ^-68.5° west and was moving ah northwest at eight knots. For the st 18 hours, the vortex was having : at*c courses and speeds of movement c l^e vicinity of Cape Cod, but the atral pressure was dropping steadily.
!<y
We,
K
Ships Race—at least from the catbird seat in Bermuda.
But, the still-little-noticed (or ignored) secondary trough of low pressure, now located 300 nautical miles to the northwest of Bermuda, was continuing to intensify and was moving southeastwardly at 14 knots.
Six hours after the time of the surface weather chart shown in Figure 6, at 1400 EDT (1800 GMT) on Saturday, 2 June, the race started as scheduled.
At that time, Bermuda’s weather was as follows: partly cloudy skies with low, middle, and high clouds; southwest winds of 15 knots; temperature 79°; excellent visibility; and barometric pressure at 1013.2 millibars (29.92 inches) and falling very slowly.
The weather forecast for the southern part of the course of the race was that the 20- to 25-knot winds would decrease to between 15 and 20 knots. Unfortunately, meteorologists seemed to be unaware of an intensifying secondary trough of low pressure approaching from the west. The forecast was a bust. As the trough approached, instead of decreasing, the winds increased to a steady 30-plus knots with much higher gusts. Westerly and southwesterly waves and swells increased rapidly to 20 feet in height.
Figure 7 is the GOES EAST geostationary satellite’s view of the weather situation at the start of the race at 1400 EDT (1800 GMT) on Saturday, 2 June 1984. (Bermuda is at the tip of the white arrow.) This secondary trough of low pressure approaching Bermuda from the west and its attendant phenomena were soon to “trigger” the Marques tragedy—only 14 hours from the time of this satellite photo.
With the passage of the cold front over Bermuda near 2000 EDT Friday night (0000 GMT Saturday, 2 June) followed by improving island weather throughout the morning as the cold front increased its distance from Bermuda, it had been erroneously assumed by meteorologists and race officials that the meteorological and oceanographic threat had passed.
At 0200 EDT (0600 GMT) on the fateful Sunday morning, 3 June, as depicted in Figure 8, the cold front had moved out of the low-pressure center, now located at 41.9° north-64.0° west, and moving east southeast at 28 knots. Central pressure of the low was 990 millibars (29.24 inches). The cold front was now 420 nautical miles to the southeast of the Marques and of no concern. The intense secondary trough, however, was only 70 nautical miles to the northwest of the barque and was moving southeastwardly at 22 knots.
The day before, the Marques was reported low in the water, but there had been no indication that the ship was in trouble. At that time, winds in the area were reported to be 20 knots gusting to 30 knots. Seas were running at 12 feet.
As the secondary trough approached the Marques, southwesterly winds increased to 28 knots with gusts to 42 knots, and waves from the southwest increased to an estimated significant height of 17 feet with a period of 8.4 seconds. With the Marques on a north northeasterly course, heading for Halifax, and the wind and waves coming from the southwest, both the wind and waves were striking the ship on the port quarter.
One crewmember, 23-year-old Jay Ash of Pennsylvania, was quoted as saying, “We had no premonition of disaster. It was terrific sailing weather; nothing to worry about. The wind had actually lessened and seemed like it would die ... . Then, right at 4 a.m., it started dousing us with rain. There was no wind change [shift]. Then, bam, right out of nowhere it hit. ... I felt the ship go bow down and blow
over. . . . The ship was down, and we were in the water in less than 30 seconds. . . . Nothing could have been done to save the ship.”
Another crewmember survivor, Bill Bamhardt, age 24, was quoted as saying, “If I hadn’t been on watch [the 0400-0800 watch], I would have been sleeping, and there would have been no way to get out. If you were on deck or near it, you survived.”
Other survivors reported that a wind of “incredible force” and two huge waves sank the ship in 45 seconds.
Philip Sefton—a 22-year-old Englishman, a professional sailor, and a member of the Marques regular crew— was at the helm when the ship went down. More than six feet tall and with muscles like a weightlifter, Sefton tried to “spin” the wheel to keep the ship upright. But he could not hold it.
He reported that the ship was on her side after ten seconds, started to go under after 30 seconds, and sank after 45 seconds.
Sefton was swept overboard as the deck of the ship plunged beneath the
sea.
Reporter Kevin Stevenson of the Royal Gazette, Bermuda’s daily newspaper, quoted Sefton as saying, “When the wind hit us, it was unexpected and incredible in its velocity. I have been in winds of 50 knots, but the one that hit us was well in excess of that. I am absolutely satisfied that nothing could have been done to save the ship.”
Just before the Marques sank at 0400 EDT that Sunday morning, she was sailing under heavily reefed sails. At the time of sinking, the intense secondary trough of low pressure was approximately 26 nautical miles to the northwest of the Marques; the cold front was 450 nautical miles to the southeast of the ship and of no more concern; and the storm center (central pressure 989 millibars [29.21 inches] and falling) was moving east southeastward at 28 knots. When the Marques foundered, the storm center was bearing 010° and 480 nautical miles from the ship.
From the weather maps and other information available, it appears that the winds at the time of the disaster were west southwesterly to southwesterly at 45 to 50 knots with peak gusts to 75 knots. Southwesterly waves increased to an estimated significant height of 20 feet. The average of the highest 10% of the waves was 26 feet, and the highest waves were 37 feet. It is also quite likely that a decaying swell of 14 to 18 feet from between west and northwest was being superimposed on the primary southwesterly waves—the “peaking” of the two trains perhaps producing what some refer to as a “rogue” wave.
Figure 9 shows the surface weather map for 0800 EDT (1200 GMT) on Sunday, 3 June—four hours after the Marques foundered and about the time that the nine Marques survivors were rescued by the 119-foot Polish schooner Zawisza Czarny, also a participant in the race. At this time, the low pressure center was located at 40.5° north-60.8° west with a central pressure of 986 millibars (29.12 inches). The low had changed course again and was now moving northeastward at 25 knots. The secondary trough had passed over Bermuda shortly before the time of this map.
The weather in Bermuda at the time of Figure 9, 0800 EDT (1200 GMT), Sunday, 3 June, was scattered middle and high clouds, visibility restricted by haze, west to west southwest winds of 20 knots with higher gusts, temperature 73°, and barometric pressure 1,009.6 millibars (29.81 inches) and rising.
Figure 10 is the GOES EAST geostationary satellite’s view of the weather at 1400 EDT (1800 GMT),
Sunday, 3 June. A look at this satellite photo shows that the cold front had no lost any of its “zip,” with the clouds of the secondary trough remaining in' tense. (Bermuda is at the tip of the white arrow.) ,
At the time of Figure 10, Bermuda weather report was missing.
Figure 11 depicts the surface weat e map for 0800 EDT (1200 GMT) on Mondary, 4 June. The intense low (central pressure now 978 millibars [28.88 inches]) was now centered at 46.3° north-50.9° west, and moving north northeast at 25 knots. The secondary trough, still intense, was now 455 nautical miles to the east of Bet' muda, extending from latitude 46.0 north to latitude 25.0° north. A new ^ low with associated frontal systems located 180 nautical miles to the sou! west of Halifax. .
The weather in Bermuda at this tl,T1 was widely scattered low and middle clouds, unlimited visibility, north northeast winds of five knots, teinper ture 72°, and barometric pressure 1,015.4 millibars (29.99 inches) and rising rapidly. A beautiful morning- Figure 12 is the GOES EAST ge0 stationary satellite’s view of the weather situation at 1400 EDT (1^0 _ GMT) on Monday, 4 June. The onP ^ nal cold front and the secondary tr°U^ are still easily identifiable, while a low pressure system is developing t0 the south of Halifax. (Bermuda is at the tip of the white arrow.) ,y
Figure 13 is a plot of the six hoU>^ positions and movement of the inte - low pressure center from 0000 Z (GMT), Friday, 1 June 1984 (Posit'0 #1), to 1800 Z (GMT), Monday, 4 June 1984 (Position #16). Note the erratic behavior of the center in the vicinity of Cape Cod. The dashed ' , from the lower Chesapeake Bay 10 , muda represents the intended track the 30-foot sloop Mirebel. The circ
166
Proceedings / Decenit>cr
STRONG OUTFLOW
MINIMUM HORIZONTAL w WIND
K- 0.2.5 to 1.6 nautical miles -H
Figure 13
Figure 14
Figure 15
Figure 16
Mth
M,
^irebel “sailors” were rescued. The ashed line from Bermuda to Halifax is
the
>ne
?day, 2 June, and at 0600 Z on Mon- 4 June.
At no time did the central pressure reach or exceed 24 millibars. The
l)Q »■ ----------- **» "v kJWV/ «
lrne during the 96-hour period did
'easfC -
L, °ne millibar per hour for 24 uurs
Thus, we cannot attribute the
an “X” shows where the four
course of the second leg of the n UI'y Sark Tall Ships Race. (The pen- sant indicates the position where the ^-rigger, Marques, foundered.) ,/as a meteorological “bomb” a key 0 the Marques tragedy? tables 1 and 2 provide the answer to ls question.
Table 1 shows the location; central Assure; and direction, speed, and °vement of the intense low pressure 'Stem every six hours from 0000 Z (Ox )’ Friday> 1 June 1984 to 1800 Z I. MT), Monday, 4 June 1984. The Position numbers” correspond to the sjtion numbers in Figure 13. of i!ble ^ sFows the pressure changes ^’he intense low pressure system for ' and six-hour periods and the aver- P.ressure changes per hour for 24- [.P six-hour periods, from 0000 Z,
Jul ^ ^une *° 1800 Z, Monday, 4
Jr*T°m Table 2, it is seen that the r8est 24-hour pressure falls occurred t)600 Z, 1200 Z, and 1800 Z on Sat-
|is _
gest six-hour central pressure falls Jarred at 0000 Z and 0600 Z on Sat- s 2 June; 0600 Z and 1200 Z on nday, 3 june; and at 0600 Z on onday, 4 June.
,,Remember, a meteorological Prc0rnb' 's defined as a deepening low sUrSsure center where the central pres, e falls average at least one millibar hour for 24 hours. r°m Tables 1 and 2, we see that at
) t— - -
the p - .
lea Cntral Pressure falls average at
Marques tragedy to a meteorological “bomb.”
There is something else to be considered, though. Remember that in describing the sinking, Marques’ survivor Jay Ash said. “We had no premonition of disaster. It was terrific sailing weather; nothing to worry about. The wind had actually lessened and seemed like it would die. . . . Then bam, right out of nowhere it hit. ...” (Italics added for emphasis.)
This may be a meteorological clue as to why the Marques sunk.
In the strong southwesterly wind field a short distance ahead (to the east) of the advancing intense secondary trough, Ash stated that “. . . The wind had actually lessened and seemed like it would die. . ■ ” One must assume from his description that the wind speed decreased fairly rapidly to only a few knots.
As any experienced sailor knows, a strong wind field—or any wind field for that matter—is not a steady state flow over a long period of time. The wind is actually a series of gusts and lulls.
But Ash’s statement goes far beyond the “gusts and lulls” description.
Is it possible that the Marques experienced the phenomenon of a “microburst”?
The term “microburst” refers to strong wind shear situations in the lower levels of the earth’s atmosphere. Wind shear is a condition where the wind changes its speed and/or direction over a small distance. The term “microburst” was coined by Professor Theodore T. Fujita of the University of Chicago in 1976 to focus on the small horizontal dimension (diameter 0.5 to 1.6 nautical miles) and intense horizontal wind flows (up to 97 knots) of some wind shear situations. Microbursts are especially hazardous— frequently fatal—to aircraft takeoff and
landing operations, but they also have their effect on ships and smaller craft.
Wind shear in the lower levels of the atmosphere is associated with land and sea breeze situations, the boundaries between air masses (weather fronts), intense low pressure troughs, strong winds blowing over rough terrain, and convective storms and clouds. A microburst usually occurs with convective storms and clouds, and these, in turn, are frequently associated with fronts and/or strong troughs of low pressure.
The microburst is a relatively simple form of disturbance in atmospheric flow and is characterized by a very strong downdraft associated with thunderstorms and cumulus congestus clouds. But sometimes microbursts occur with cumulus clouds that are neither large nor intense enough to produce lightning or heavy rain. The downdraft usually has a visible rain shaft associated with it, but this is not always the case. When and where the downdraft reaches the earth’s surface, it spreads out horizontally (Figure 14). Sometimes the rain shaft evaporates before reaching the earth’s surface, leaving the downdraft invisible.
Microbursts tend to intensify in about the first five minutes after impact with the earth’s surface and have the following characteristics:
► Horizontal dimension: 0.5 to 1.6 nautical miles
► Duration: Five to 15 minutes, severe wind shear for approximately two to four minutes
► Wind differential: From an average of 49 knots to a maximum observed (by Doppler radar) of 93 knots
Intense troughs of low pressure in the atmosphere are notorious areas of strong instability and heavy convective activity. From Ash’s statement that “. . .the wind seemed like it would die. . . ,” one might assume that a
Table 2 Twenty-four hour and six-hour pressure changes, and 24-hour and six- hour average pressure changes per hour, of the intense low pressure system from 0000 Z (GMT) Friday, 1 June 1984 to 1800 Z (GMT) Monday, 4 June 1984. Pressure Pressure Average Pressure Average Pressure Change Change Change Per Hour Change Per Hour (Millibars) (Millibars) (Millibars) (Millibars) DayIDatelTime Last 24 Hours Last 6 Hours Last 24 Hours Last 6 Hours | ||||
Fri 01 Jun 84 |
|
|
|
|
OOOOZ |
|
|
|
|
0600Z |
| -01 |
| -0.17 |
1200Z |
| ±00 |
| ±0.00 |
1800Z |
| -02 |
| -0.33 |
Sat 02 Jun 84 |
|
|
|
|
OOOOZ | -07 | -04 | -0.29 | -0.66 |
0600Z | -11 | -05 | -0.46 | -0.83 |
1200Z | -13 | -02 | -0.54 | -0.33 |
1800Z | -11 | ±00 | -0.46 | ±0.00 |
Sun 03 Jun 84 |
|
|
|
|
OOOOZ | -03 | +04 | -0.13 | +0.66 |
0600Z | -02 | -04 | -0.08 | -0.66 |
1200Z | -04 | -04 | -0.17 | -0.66 |
1800Z | -04 | ±00 | -0.17 | ±0.00 |
Mon 04 Jun 84 |
|
|
|
|
OOOOZ | -08 | ±00 | -0.33 | ±0.00 |
0600Z | -12 | -08 | -0.50 | -1.33 |
1200Z | -08 | ±00 | -0.33 | ±0.00 |
1800Z | -09 | -01 | -0.34 | -0.17 |
down the open hatches, the ship in 45 seconds.
Table 1 Locations, central pressures, and direction and speed of movement of the intense low pressure system during the period 0000 Z (GMT) Friday, 1 June 1984 to 1800 Z (GMT) Monday, 4 June 1984. The “position numbers” correspond to the
position numbers DayIDatelTime | on Figure 13. Latitude, Position Degrees Number North | Longitude, Degrees West | Central Pressure (Millibars) | Direction & Speed (Kts) of Movement | |
Fri 01 Jun 84 | |||||
ooooz | 1 | 37.2 | 71.1 | 1004 | NNE @ 23 Kts |
0600Z | 2 | 39.6 | 70.1 | 1003 | NNE 12 |
1200Z | 3 | 40.6 | 69.7 | 1003 | NNE 17 |
1800Z | 4 | 41.1 | 69.0 | 1001 | SSE 18 |
Sat 02 Jun 84 | |||||
OOOOZ | 5 | 40.5 | 68.0 | 997 | NNW @ 13 Kts |
0600Z | 6 | 41.8 | 68.8 | 992 | SSE 11 |
1200Z | 7 | 40.7 | 68.5 | 990 | NNW 08 |
1800Z | 8 | 41.3 | 68.8 | 990 | SE 14 |
Sun 03 Jun 84 | |||||
OOOOZ | 9 | 40.6 | 67.2 | 994 | ENE @ 30 Kts |
0600Z | 10 | 41.9 | 64.0 | 990 | ESE 28 |
1200Z | 11 | 40.5 | 60.8 | 986 | NE 25 |
1800Z | 12 | 42.0 | 58.0 | 986 | ENE 30 |
Mon 04 Jun 84 | |||||
OOOOZ | 13 | 43.4 | 54.6 | 986 | ENE @ 18 Kts |
0600Z | 14 | 44.2 | 52.4 | 978 | NNE 23 |
1200Z | 15 | 46.3 | 50.9 | 978 | NNE 25 |
1800Z | 16 | 48.7 | 49.5 | 977 |
|
To convert millibars to inches of mercury, divide millibars by 33.86. 1004 millibars -r | 33.86 = 29.65 inches of | ||||
mercury. | |||||
sank of
heavy convective cloud containing a microburst and traveling toward the northeast in advance of the secondary low pressure trough passed over the Marques.
But an encounter with a microburst is only a small part—a very small part of the overall disaster “equation.” Other factors to be considered are the unusual silhouette which the three- masted, square-rigged barque presente to the wind and the Marques being l0"1 in the water.
With the ship low in the water, the aft one-third of the ship presented a much greater hull sail area to the win than the forward two-thirds of the ship’s hull (Figure 15). And with the ship on a north northeasterly heading and west southwesterly to southwester j winds of 45 to 50 knots with gusts aS high as 75 knots pummeling the ship on the port quarter (from 246° relative;' a tremendous pressure varying from 13.5 to 34.1 pounds per square foot was being exerted primarily against t stem area.
The southwesterly waves had a sig nificant height of 20 feet, and the ave age of the highest 10% of the waves was 26 feet. ,
The Marques had 17 inexperience » young students and sea cadets on boa as crewmembers. No doubt, several-'' perhaps many—of them were seasic ' below deck. The tendency would be open all hatches “to let fresh air in and get all possible ventilation.
Another factor. Even though sailing under reduced sail, the Marques pre' ^ sented considerable canvas to the Wi (Figure 16). The combined effect on exposed canvas and the aftercastle o the strong gale southwesterly winds with gusts reaching 75 knots rolled ship onto her beam ends and buried bow. The tremendous pressure exer*e by the wind on the aftercastle of the bow-down Marques would have ftm steepened her angle of descent.
With waves ranging from a sign1 cant height of 20 feet to a maximum possible height of 37 feet, a 75-kn°t|C| gust of wind and a 37-foot wave con have struck the port quarter of the s simultaneously and driven the ship under water. With water cascading
If the development and intensity the secondary trough of low pressu on Friday, 1 June 1984 had been de tected early and if the plight of the Mirebel had been known, would ® Cutty Sark Tall Ships Race have be held? Perhaps we shall never kno'*'-