TRINITY II ACCIDENT
This narrative is developed from a US
National Transport Safety Board report published on April
9th 2013, plus articles from the Australian press relating
to the Mermaid Vigilance.
The Trinity II at work
- from Marine Traffic.
The Trinity II accident might have passed under the
radar of everyone outside the Gulf of Mexico, had it not
been for the court case which had involved the Mermaid
Marine vessel the Mermaid Vigilance, one of the ships hired
by the survey company Geokinetics, and which was apparently
assigned to act as a standby vessel in the worsening weather
conditions as Hurricane Nate developed.
The Trinity II was a liftboat, one of two hired by
Geokinetics to act as a collecting point for some seismic
work being undertaken in the south of the Gulf of Campeche,
some 15 miles from the coast in 84 feet of water. The
process being carried out was for a number of chartered
vessels to lay cables containing geophones on the seabed,
and then for one of them to fire of an air gun. The
resulting seismic information would be collected on board
the liftboats. Geokinetics were working for PEMEX the
Mexican state oil company.
The Trinity II was a small craft, capable of moving
from place to place by means of its own propulsion, and then
able to jack itself out of the water on its three legs.
There were two legs at the bow and one at the stern, all 145
feet long. It had tankage for water and fuel in the hull,
and a deck house on three levels which offered a navigation
bridge, accommodation and recreation spaces for the four
crew and six contractors who were employed by Geokinetics.
The seismic activity was controlled from a container on the
deck. Liftboats are much used in the Gulf of Mexico and in
the Arabian Gulf for maintaining the small offshore
platforms which are the predominant means of recovering
hydrocarbons from beneath the seabed. The personnel on board
consisted of four crew, the master, the mate, an AB and an
ordinary seaman (All Americans). And six Geokinetics
contractors, a day navigator (Bangladeshi), a night
navigator (Australian), two quality controllers QC1 and QC2,
a cook and a cleaner (All Mexicans).
The liftboat carried the following lifesaving equipment,
three lifefloats which were buoyant ovals with netting in
the middle, one rescue boat (Although listed in the report
there is no further mention of this equipment), three
lifebuoys, two 25 person liferafts and one EPIRB (Emergency
Position Indicating Radio Beacon). The two liferafts were
not part of the vessel’s original equipment, but were
required to be installed by the US Coast Guard since the two
liftboats were to go “foreign”, ie to the Mexican part of
the Gulf of Mexico.
The US Coastguard had certified the Trinity II as an
‘offshore supply vessel with moveable legs capable of
raising its hull above the surface of the sea”. Because of
its limited size it was not required to conform with SOLAS,
but the Coast Guard had made the following restrictions on
• Maximum operation water depth 100 ft.
• Maximum allowable draught 6 ft.
• Maximum wave height when afloat 5 ft.
• Vessel not to be trimmed by the bow at any time.
• Route: Oceans, limited to Gulf of Mexico not more than 12
hours from harbour of safe refuge or location where the
vessel may elevate to survive 115 mph winds.
The timeline for the event was as follows. All in 2011:
Late August 2011. The Trinity II is located about 15 miles
North of Frontera in the Gulf of Campeche in 84 feet of
water and starts work.
September 4th. The marine weather forecast indicated the
possibility of a low pressure system forming nearby. The
master and the navigator discussed the possibility of moving
the vessel closer to the coast, but decided not to carry out
the move due to the time involved.
September 5th. There is an increase in wind speed and sea
September 6th. The National Hurricane Centre (Located at
Florida International University) reports that there is a 20
percent probability that the low pressure system close to
Trinity II will deepen. The day navigator on the liftboat
determines that the worsening weather will not affect
1200. September 6th. The sea state has become such that the
vessel can no longer be moved. Specifically it can not
undertake the transit from the elevated to the afloat
status. This is limited by US Coastguard instruction to be
carried out in no more than 5 foot swells.
Evening. September 6th. The vessel is jacked up further from
the sea surface three times. This now the only option for
the crew apart from evacuation. The precise extent of the
jacking operations were not recorded.
September 7th. NHC predicts that there is a 70% of 8-10 foot
seas. There is now no chance of jacking down for at least a
couple of days. The vice president of Trinity Liftboats
calls the master to discuss the situation. The master also
speaks with the president of Trinity and the Geokinetics
project manager in Frontera. The project manager tells him
that PEMEX can send a helicopter from Ciudad de Carmen to
evacuate the crew if necessary.
On this day Geokinetics cease operations due to the weather
and the vessels involved apart from the Mermaid Vigilance
return to Frontera. The Mermaid Vigilance is instructed to
stay in the area and act as a standby vessel “to assist if
necessary”. This information conveyed to the Trinity II
PM. September 7th. The crew of the liftboat note that the
windspeed has increased to more than 50 mph, and the NHC
have determined that this is a tropical storm, named “Nate”.
The stern leg is sinking deeper into the seabed, probably
due to wave action on the underside of the hull.
Evening September 7th. The radio controller for Geokinetics
asks that the three vessels still at sea, the Trinity I,
the Trinity II and the Mermaid Vigilance
report in every 15-20 minutes. The master is determined that
it is time to evacuate the unit, and conveys this
information to Geokinetics in Frontera. The master of the
Mermaid Vigilance is requested to close up with the
liftboat, but replies that he may be unable to do so, being
unable to turn in the adverse weather.
Night September 7th. The master of the Mermaid Vigilance
reports that he will be unable to assist the Trinity
II. He says he will be unable to turn his vessel due to
the sea state, the vessel has sustained storm damage and he
has an injured crew member on board. He returns the vessel
Early September 8th. The master of Trinity II gathers
all personnel and discusses the possibility of abandoning
ship. Also during this period of darkness in increasingly
difficult weather conditions the master is in frequent
contact with the president of Trinity liftboats by the
satellite phone. They discuss the means by which additional
air gap can be gained, but nothing is actually done.
Early Morning. September 8th. The Trinity II stern
leg penetrates a further six feet into the seabed. The
master attempts to level the hull by lowering it on the
forward legs, but this action is unsuccessful. The vessel is
stuck about 20 feet above the sea, and the hull is still
being buffeted by waves. Discussion takes place between the
president of Trinity Liftboats and the master, and the two
consider the possibility of the stern legs breaking off. The
president thinks that the result of this would be that the
vessel would only gradually fall stern first into the sea
and, according to the master, tells him to inflate one of
the liferafts. The president later denies giving this
0600. September 8th. Geokinetics in Frontera receives
another request that personnel be evacuated from the vessel.
Geokinetics contact the PEMEX “Control Marino”, which
monitors and directs all PEMEX chartered vessel movements in
the Gulf of Campeche. Control Marino dispatches Isla del
Toro and Bourbon Artabaze in the direction of the
Trinity II. Their ETAs are 1400 and 1500 on 8th.
Morning September 8th. All personnel muster wearing
lifejackets. They have collected food, bottles of water and
the flares in preparation for abandonment. The AB and others
are sent to inflate the starboard side liferaft. They place
the container on the deck, tie the painter onto the handrail
and inflate it. The high wind immediately carries it away,
breaking the painter.
1225 September 8th. The stern leg breaks off after the
impact of several large waves resulting in the stern
descending towards the sea. The master orders abandon ship,
and broadcasts a ‘Mayday” on the ship’s radio. The personnel
grab their supplies and head for the main deck. As they
approach the second liferaft a wave hits the mate and knocks
him to the deck. The master returns to the bridge to recover
the EPIRB, but is unable to do so due to the possibility of
being hit by the crane.
A wave crashes into the port side liferaft canister, and it
inflates on the deck. The crew push it over the side, but
despite it being tied on to the rail by its painter, the
wind and waves carry it away and it is soon out of sight.
(The NHC determined that the wave height at the Trinity II
location might have been as high as 36 feet.)
Two of the contractors return to the upper deck and recover
one of the three lifefloats and pass it down to the people
on the main deck. Shortly thereafter the hull is hit by
several large waves, and the master, believing that capsize
is probable, orders everyone to abandon. The cook wishes to
retrieve a second lifefloat, but everyone else enters the
water and he does not want to be left behind. None of the
prepared supplies are taken although they do take extra
lifejackets and a lifebuoy. The master has a waterproof
radio which he loses as soon as he enters the water.
Overnight to 9th September. All 10 personnel cling to the
lifefloat as it drifts in heavy seas and high winds. The
ignite their chemical lights on the lifejackets.
Morning 9th September. They drift within about half a mile
of a platform but the current changes and they drift away
again. During the day they take turns at lying across the
lifefloat two at a time. For unknown reasons the night
navigator keeps untying himself and drifting away.
2330. 9th September. The night navigator becomes separated
from the group and despite their efforts he disappears into
10th September. The weather improves but the condition of
the survivors begins to deteriorate. The day navigator is
not making any sense when he speaks.
Evening 10th September. The Ordinary Seaman inexplicably
removes his lifejacket and tries to jump out of the
lifefloat. The others secure him to it, and check on him
periodically. Later they find his face underwater, and their
attempts to revive him are unsuccessful. They secure his
body on the lifefloat.
Morning 11th September. They see a platform and the master,
mate and AB decide to swim towards it, leaving the four
weaker personnel still clinging to the raft.
Late morning 11th September. The mate begins hallucinating
and sticking his head underwater. And later the AB thinks he
sees and orange coloured vessel in the distance and so he
and the QC1 decide to swim towards it. The vessel is the
1145 September 11th. The Bourbon Artabaze spots the
lifefloat still with the cook, the QC2, the day navigator
and the cleaner alongside. They recover all four to the ship
together with the body of the ordinary seaman.
1242 September 11th. The Bourbon Artabaze recovers
the QC1 and the AB just under a mile from the lifefloat.
1500 September 11th. The Bourbon Artabaze recovers
the body of the mate. At the same time the Spanish
registered support vessel Arbol Grande arrives on
scene and rescues the master.
All survivors are airlifted to the PEMEX hospital in Ciudad
de Carmen. The day navigator later dies. A week after the
accident the body of the night navigator is recovered.
Subsequent to the evacuation the remaining legs of the
Trinity II break off and the vessel drifts for several
days before being boarded by units of the Mexican Navy and
towed back to Ciudad de Carmen. Its AIS system remained
operational and this allowed it to be tracked.
The report goes into some detail about the manner in which
the investigation took place. After some initial problems
during which the Mexican authorities refused permission for
the team to carry out its task the NTSB team made several
visits to Ciudad de Carmen and interviewed members of the
Geokinetics team and well as visiting the Trinity II, which
was lying alongside in Ciudad de Carmen, more than once. The
also went to Lafayette and interviewed the remaining crew
members of the vessel and the management of Trinity
The US Coast Guard were also involved and a Coast Guard SAR
group went to Mexico City and attempted to interview the
members of SEMAR (Secretaria de Marina – Mexican Navy). The
NTSB team also requested permission to interview the SEMAR
personnel in Ciudad de Carmen who had been involved, but the
permission was not granted, and in the end the investigators
had to be satisfied with a Powerpoint presentation relating
to the processes involved and the equipment deployed. They
also unsuccessfully attempted to interview the personnel who
had been on duty from PEMEX Control Marino and CRAE (Centro
Regional de Atencion and Emergencies – PEMEX emergency
response operations centre). The report also goes on to
state that the Coast Guard group in Mexico City had produced
a report, but that the NTSB had been unable to have a copy
of it, although they had been able to view it in Washington
DC. This seems quite difficult to understand.
However, regardless of the information made available by the
Mexican authorities, during the event there was almost
constant interaction between them and the Coast Guard Eighth
District who had been contacted soon after the abandonment
by the Trinity Liftboats vice president. They offered
assistance in the form of a C-130 aircraft, but the offer
was refused. SEMAR stated that they had dispatched two 45 ft
vessels towards the scene.
On 9th September the Coast Guard applied further pressure on
SEMAR who responded with a list of assets deployed these
• One MI17 helicopter
• Two Panther Helicopters
• Two motor lifeboats
• Five Interceptor Patrol Vessels
• One fixed wing aircraft.
The Eighth District also received occasional screenshots of
the SEMAR search patterns, and this allowed them to validate
the process in general. And on September 11th they received
permission to deploy the C-130. However about ten minutes
after the aircraft had taken off the recovery of the
lifefloat was announced.
In terms of cooperation with the investigation the report
As a result of the limited information available from
Coast Guard SAR personnel, SEMAR, and PEMEX, the NTSB’s
investigation of the Trinity II accident was hampered.
Neither Coast Guard nor NTSB accident investigators were
able to ascertain how the search was planned and
coordinated, and how this may have affected the rescue of
the Trinity II personnel.
The investigation considered hurricane planning on the part
of both Geokinetics and Trinity. Both plans were phased, the
phases relating to the approach of a hurricane from outside
the area of operation, with the Geokinetics place requiring
the complete evacuation of the offshore installations if the
hurricane came within 250 kilometres of the location. It
also identified ports of refuge for all vessels, but did not
account for the time which it would take for the liftboats
to get to safety. The Trinity plan also required the
evacuation of its units if gale force winds were to be
expected within 36 hours.
It is worth noting that the investigators found fault with
the weather forecasting which always limited the risk of
extreme weather and never forcast the wind strengths
actually experienced at the Trinity II location. But
in the end neither plan considered the possibility of a
hurricane developing in the area of operations.
The Trinity II had a Marine Operations Manual which
also contained heavy weather information, and in that manual
phase 3 required the master to evacuate the unit in the
event that it was in the direct line of the storm. In the
end none of the emergency plans were put into operation.
Some of the conclusions of the investigating body were as
• The master’s decision that all personnel on board the
Trinity II abandon the vessel once the stern leg failed was
understandable, given the context of the situation.
• The actions taken by the Trinity II crewmembers when
abandoning the vessel were of limited effectiveness because
the stressed and exhausted crew did not make use of all
available safety equipment and supplies, and this reduced
the personnel’s probability of survival.
• Had the Trinity II crewmembers brought along and activated
the emergency position indicating radio beacon when the
personnel abandoned the vessel, it would have aided the
Mexican search and rescue effort and shortened the time the
personnel had to spend in the water, thus increasing their
probability of survival.
• The inappropriate decision to inflate the starboard-side
liferaft on deck, and the inadvertent loss of the portside
liferaft, led to the loss of both of the vessel’s available
out-of-water flotation devices and the additional lifesaving
supplies contained therein.
• The weather preparedness plans of Trinity Liftboats and
Geokinetics in place at the time of the accident did not
adequately address weather systems such as rapidly
developing surface low pressure systems and nontropical
storms, nor the operational limitations of each individual
The investigating team also made a number of recommendations
directed to the US Coast Guard, the US Department of State,
the Offshore marine Service Association, Trinity Liftboats
and Geokinetics. They were all concerned with the following:
The need to improve co-operation between the US and Mexican
authorities in the event of a marine accident, the
requirement that proper guidance is provided for the
deployment of ‘throw over’ liferafts, and that adverse
weather planning take into account locally developing low
THE MEDIA INVOLVEMENT
In early 2012 the Australian press reported on the
involvement of the Mermaid Vigilance in the
Trinity II accident, probably because some of the
families of those who lost their lives were suing everyone
involved including the ship and its master. He was accused
of abandoning the crew of the liftboat and more extremely
“murder at sea”. One of the navigators was Australian, and
Mermaid Marine is an Australian company. Mermaid made a
statement in March 2012 that the master had made the
difficult decision of not going to the aide of the
Trinity II because his primary responsibility was to his
passengers and crew, one of whom had been said to be injured
during the event, and all of whom, were suffering from acute
seasickness. Also that the equipment on the deck would have
made the any intervention dangerous, starting with problems
in turning the vessel.
Mermaid also stated that at no time did the Mermaid
Vigilance receive a request from the Trinity II
to go to its assistance, although it did receive repeated
requests from Geokinetics onshore control.
Also, in 2012 the Australian Seven Network’s “Sunday Night”
programme broadcast what it described as an ‘Explosive
Investigation” broadly along the same lines that have
already been described’. Mermaid Marine had provided the
programme with a response but the presentation had ignored
it. This resulted in a formal complaint by Mermaid being
upheld by the Australian Federal Court in July 2014.
WITH THE ADVANTAGE OF HINDSIGHT
Oh dear, where to start. Those of us who have been involved
in the development of processes designed to keep people safe
offshore mostly concentrate on the means by which emergency
events might be prevented, and then afterwards on the means
by which the survival of the personnel in the event of the
realization of the hazard can be achieved.
To start with the Trinity II and if it comes to that
all its sister vessels, seem to be so small. Their ability
to move from place to place is virtually limited to calm
conditions and one would think that they would have problems
preloading, which for those unfamiliar with the operation of
jack-ups is the means by which the footings are tested. Four
legged jack-ups can do this by raising all but one of their
legs a bit and seeing if the loaded leg goes through the
seabed. Three legged jack-ups usually pump a great deal of
water into talks surrounding each leg in turn. This
simulates extremely high winds impinging on the hull, and
ensures that in extreme weather the footings will hold.
But we know now that the footing for the aft leg did not
hold. This was as a result of the high winds and waves to
which the vessel was subject. By then there was no
possibility of jacking down and running for a safe haven.
The Captain was extremely experienced, but up until the
event might have only operated within the US administered
area of the Gulf. Where there were two things different from
the situation in Mexican waters. The first is that
hurricanes seldom if ever (we might need to check on that)
originate in the northern part of the Gulf, and the second
thing is that everyone is supported by the virtually
unlimited resources of the US Coast Guard.
So firstly should this vessel of very moderate capabilities
have been sent into the Gulf of Campeche in the beginning of
the hurricane season? Since Geokinetics have, subsequent to
the accident, changed its operating process to replace
liftboats with monohulls with four point moorings the answer
is a resounding no.
Secondly could they have relied on the weather forecasting
and their own meteorological skills to jack down and find a
port of refuge before the unset of adverse weather? The
quick answer if probably not, and we have no idea of what
actually passed between the master and the management of
Trinity Liftboats during the period before the emergency.
Were the president and vice president of the company
proffering advice? In which case what were their
qualifications and experience such that this might be
meaningful. The master seems to have consulted the day
navigator about the weather on a number of occasions. What
meteorological qualifications did he have? We don’t not
know, but it is common practice for the personnel who look
into the computer screens and manipulate the software during
these sort of operations to be known as “navigators”. In any
case it is almost certain, that due to the restrictions on
the operation of the vessel, any opportunity to jack down
and run for safety would be missed in a rapidly developing
local weather system.
The fall back position in the event of extreme weather was
considered in all the hurricane preparedness procedures to
be evacuation of the unit, but this was never requested
until the lives of those on the liftboat were in danger. In
any case the standard means of evacuation was apparently by
ship, with all the personnel except for the crane driver
being lowered onto the deck of a vessel a few feet from the
legs and then the unfortunate crane man shinning down a
knotted rope, to be picked up from the sea. The Trinity
II did not have a helideck, so the crew would have to be
winched aboard a helicopter. Had this been considered as
part of the routine evacuation for an approaching hurricane,
or even as an emergency measure? We have no idea, but we do
know that the Mexican navy had at least one helicopter with
winching capabilities available because one was used to put
people on the unit when it was floating about unattended.
But maybe while we, in hindsight are aware that a tragedy
was about to occur, the people who organized the operation
thought “15 miles out – what can go wrong?”.
As the weather got worse Geokinetics took action to
safeguard their fleet sending all back to port but asking
the Mermaid Vigilance to remain at sea, either
to act as a standby vessel at the Trinity II, or to
stand by the Trinity II. It is likely that the owners
would say that the it was the latter, since the requirements
are different. And anyway how could the Mermaid
Vigilance act as a standby vessel? It was not suitably
equipped. And here is another unanswered question, what made
the Geokinetics marine controller select the Mermaid
Vigilance over the other vessels of their fleet. Was it
the most suitable, or the largest or what? In any case, when
it came to it, the ship was miles away from the liftboat,
and the master felt that he would be unable to turn and get
close to it without hazarding his ship and its crew. Hence
the media interest in Australia. There is not much more to
say about this, and a ship master must put his own ship and
its crew first. However, we can assume that he did not
really think he would be called to do anything, otherwise he
might have refused when asked, and this would have given
Geokinetics the opportunity of choosing an alternative.
One should bear in mind that the NTSB investigators were
unable to interview any of PEMEX marine controllers or the
SEMAR personnel who had been directly involved in the
incident, and so the most important question remains unposed,
and therefore unanswered. This is – why did PEMEX not
arrange for a suitably equipped helicopter to fly out and
recover the crew of the Trinity II by winching? There
may be an answer, and this could be that the master had not
broadcast a mayday message, and that therefore the situation
could not be deemed to be critical.
So by now the scene was set for the major drama in this
tragedy, and the errors made during the time up to the
evacuation into the sea are obvious. These errors, mainly on
the part of the master, were made, it is suggested by the
investigators, by his extreme fatigue. The US Coast Guard
made some recommendations to prevent such an occurrence
again, particularly that the guidance for the operation of
throw-over liferafts should be reinforced. But there is no
doubt that the master’s most serious error was not to take
the EPIRB with him. If he had the lifefloat and the ten
personnel clinging to it, would have been found within
One cannot help thinking that the antipathy between the
American and the Mexican authorities did not provide the
best opportunity for learning from the event. Some say that
this is at least in part due to the fact that an American
lawyer spirited the survivors away in his Learjet before the
Mexican authorities had the opportunity of interviewing
them. It also seems possible that all was not sweetness and
light between the NTSB and the Coast Guard, illustrated by
the fact that the Coast Guard were reluctant to share the
information gained from SEMAR in Mexico City, and that the
NTSB chose identify a previous recommendation which had been
less than effective.
This related to the liftboat AVCO V which sank in
1989 while trying to return to port during Hurricane
Chantal. 10 of the 14 personnel on board died. As a result
the NTSB issued a safety recommendation to the Coast Guard.
Require that liftboats have on board a severe weather
action plan that is tailored to the operating
characteristics and limitations of the vessel.
The Coast Guard issued regulations requiring heavy weather
guidance to be included in liftboat operations manuals, in
1996. And there was indeed heavy weather guidance in the
Trinity II Operations Manual, but it was of limited
value to the master of the vessel since it dealt solely with
an approaching hurricane, rather than a developing weather
system at the location.
This narrative has required some interpretation from the
original report, and also contains the views of the author,
it therefore cannot have any legal standing. US legislation
also precludes the admission into evidence of the report, or
its use in any civil action for damages.
Victor Gibson September 2014
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