M.V. Trident Trip – Gulf of Thailand
03 April – 12 April 2007
The inaugural
”Hammerhead Tour”
The Plan ...
… was to work through a list of 12 marks the guys from MV Trident had compiled previously, using the logs from USS “Hammerhead” and marks given by local fishermen. The trip was planned as an expedition/exploration trip – no guarantees for success! All dive sites are in an area approximately 110nm east of Koh Samui, in the Gulf of Thailand, in the middle between Thailand and Cambodia.
The preparations
Our group from Australia shipped in excess of 300kg dive gear via FedEx from Sydney to Koh Samui, including the Inspiration tanks, a booster pump, wetsuits, fins, 1st and 2nd stages, reels, SMBs, … Naturally!??? We had to pay import tax!
MV Trident had sourced sorb, Helium and Oxygen cylinders from a few friendly sources for this trip (the longest trip MV Trident has done so far for a group of 10 divers).
When we arrived on board, our gear was already there. Unfortunately, the boxes were in a bad shape – broken pieces (including one torch battery) … Next time, we’ll use tougher boxes! One of us had “forgotten” his rebreather in Bangkok – he did not check his luggage through to Koh Samui … Doh! We also had at least once box with dive gear getting lost. Poor old Dave had to borrow fins, socks (instead of booties), etc.
Diving in the Gulf of Thailand
The bottom of the Gulf is very flat, with the depth on average in the 80m range and covered with very fine silt from the rivers in the region. At shallower depths, we had viz of up to 50m, at the bottom we had anything between 0 and maybe 30m. Water temperature was 29°C close to the surface, down to 24°C at the bottom. The weather was expected to be calm at this time of the year – surprisingly, we had a few thunderstorms, with waves of up to 3m, had to dive in up to 2.5m waves
The Vessel 
MV Trident is an ex-German Coastguard vessel, approximately 30m long and 5m wide. The lower deck consists of cabins, toilets and showers. The middle deck is the wheelhouse, a large room with TV/DVD, workbench and storage space, kitchen and the dive deck at the stern. The upper deck is where the meals are served. The inside and lower rooms and below deck cabins (max 3 people per cabin) are air conditioned.
On board is a constant flow Nitrox/Trimix panel. Partial pressure blending is also possible. Since our trip, MV Trident now sport a booster pump for 200bar Oxygen fills.
At the stern of the vessel is plenty of space for the divers to store their gear and to gear. With 10 divers, it got crowded before dives. Fresh water for rinsing of your dive gear is also available. MV Trident carries a chase boat, which we did have to use a few times.
At the stern a diving platform allows easy access to the water. At the dive site, the crew tie the anchor line onto the wreck, before the divers get into the water.
From the website (
Tech Thailand » Boat):
“M.V.Trident was built for the German Navy and used as a Coastguard cutter in the Baltic Sea. She was sold to Thailand and used by Thai Customs before being sold and converted for diving use. She is a stable comfortable vessel with lots of room to relax in between dives. For technical divers we can blend any Trimix blend, Nitrox to 40% and deco bars supply oxygen at 6m and shallower. For CCR divers we can supply sorb and oxygen boosted to 200 bar - and a clean dry place to repair your unit!” The wrecks:
Tottori Maru
A freighter, one of the Japanese “Hell ships”, sunk in 1945 by USS Hammerhead, while empty on route.
Nanmei Maru
A tanker, sunk by USS Hammerhead in 1945.
Sakura Maru
A bulk carrier, sunk by USS Hammerhead in 1945.
03 April
After an uneventful flight from Bangkok, I arrived at what must be the most beautiful airport in the world. Koh Samui Airport is a collection of open buildings (no walls or windows – just a roof on pylons) – it looks like a modern gateway to paradise. Something had gone wrong – there was nobody to pick me and my big Inspiration box and the two backpacks up at the airport. After some deliberation I decide to catch a taxi and go to “Big Buddha Beach”. (If you haven’t been there, do pay a visit to the big temple before or after your trip! It is very impressive!) When I finally arrive at the boat, I thoroughly enjoyed the welcome beer
The rest of the Ozzie contingent arrive one after the other and late at night we “set sail” and leave the harbour.
04 April 
The Tottori Maru is one of 20+ so called “Hell ships”, which were used to transport POWs during WWII. She was empty when sunk by USS Hammerhead. Please read
Photographs and Memorabilia
US-Japan Dialogue on POWs
Jim's diary
and many other sites that describe what the POWs had to go through on board of ships like the Tottori Maru!
During the preparations for the 1st dive (turned out to be a “rubbish” steel wreck), I found out that the Inspiration ADV rubber diaphragm is punctured and the unit does not hold +/- pressure. No idea why and how this happened … Fixed it with a double layer of “GladWrap” and disabled the ADV. The fix lasted for the entire trip.
For all the next dives, I plugged my DIL into the manual DILL add (fortunately, the female part of a standard LP inflator hose fits the male part of the APD manual inflator). We dive what we believe is the “Tottori Maru”, sank by USS “Hammerhead” in 1945. The anchor line is tied in on port side near the bow. Swimming towards the wheelhouse, extensive torpedo damage becomes visible on the starboard side near the forward cargo hold. The wreck has a list towards starboard, with the bow almost lying on starboard side. Parts of the wreck are covered in beautiful coral trees – quite a sight! Great viz at 30m+ just above the wreck, approx 10m+ at the wreck – viz changed once we started working …
On the starboard side, near the wheelhouse is the funnel, also some sort of long beams (cranes?), and lots of debris.
Dive #1: skipped
Dive #2: 74msw, 83min, DIL: 15/50, SP: 1.30
05 April
We are still on what we think is the “Tottori Maru”. During the 1st dive today, I looked at the bow port section, searching for the name of the ship – nothing to see. Then swam around the bridge area and the debris field just off the wreck on the sand, inbetween wreck and funnel. Found a telegraph next to the funnel, with the indicator in 1 o’clock position, no lever.
2nd dive – searched from bridge to the stern, viz 15m+ at the stern – nobody there to disturb the mud!. Found stern binnacle right below the stern of the wreck on the sand! The stern of the wreck is in good condition and upright. The shape of the stern looks very much like in the picture of the “Tottori Maru”. Unfortunately, I did not look for the props (how stupid!)
Dive #3: 75msw, 162min, DIL: 15/50, SP: 1.30
Dive #4: 74msw, 86min, DIL: 15/50, SP: 1.30
06 April
Over night we had a storm. Big waves today, up to 2..2.5m! Initially I was not sure whether I wanted to dive in these conditions. After talking each other up, we all decide to take a dip.
1st dive – Dived down the shotline which marked the place where the binnacle was – found it following the line the shot made in the mud for about 20m. Then Frits’ Inspiration went wild – ppO2 at 1.85! Beep .. Beep … I started preparing his and my bailout and wanted to send him back to surface. Frits was very calm and started to make his way back to the shotline. I followed him in 0 viz (we had stirred the mud when swimming to the binnacle). By that time Frits was back on the loop – his solenoid obviously now working again. We did a blue water ascent near the shotline – great buoyancy drill.
2nd dive – We found bottles and crockery near the bridge, including a ceramic bottle with “JM Saigon” written on it, a rice bowl and a cast iron bell with brass plating (or paint?) but no name on it. Bazza confirmed the “Oyster” shape of deck/hull cut-outs forward of and behind wheelhouse area – like in the picture of the “Tottori Maru”.
Dive #5: 75msw, 82min, DIL: 15/50, SP: 1.30
Dive #6: 74msw, 127min, DIL: 15/50, SP: 1.30
07 April
We left the “Tottori Maru” and moved to our next mark, a wreck believed to be that of “#5 Nanmei Maru”, a tanker sunk by USS Hammerhead in 1945. The 1st dive I had to abort, because MV Trident had drifted off the wreck due to a poor tie in.
2nd dive – in avg viz. We found many pipes on the deck of the wreck, which is almost completely netted. Oysters everywhere. This is a much smaller wreck. There are some small open hatches but nothing visible inside.
Dive #7: 14msw, 4min, DIL: 15/50, SP: 1.30 - aborted
Dive #8: 73msw, 81min, DIL: 15/50, SP: 1.30
08 April
We moved on to our next mark, the wreck of what we believe is the “Sakura Maru”, a bulk carrier. The ship was sunk by USS Hammerhead in 1945. During the 1st dive, we check out the cargo holds which appear to be empty. After a lap around the wreck, we found heaps of broken porcelain at the bow, a petroleum lamp with the glass screen, glass lamp shade from an electric light, Nestle glass jar!! (maybe from a fisherman) and some broken porcelain at the stern. Part of the stern looks as if it was sheared off, again there is lots of netting. The stern section has multiple entry points – maybe for the next dive, I don’t have the guts … yet.
On our 2nd dive we explore the port side more closely. Multiple holes are visible along waterline, maybe from surface fire (which would be in line with Hammerhead’s records. Again, we check out the stern section – Frits wants to look inside, I check out the deck in the hope to be able to dig out something interesting. The wooden deck is still in place in many parts of the wreck, but there was nothing of interest.
Dive #9: 74msw, 138min, DIL: 15/50, SP: 1.30
Dive #10: 71msw, 92min, DIL: 15/50, SP: 1.30
09 April
Our first target for today turned out to be a fish attractor, a concrete block with rope and a float on the surface, with palm leaves attached to the rope. Looks like a palm tree in the middle of the ocean! No point diving that
J
We continued to go through our list of marks and our 1st dive for the day turned out to be a steel trawler, upright, in very good condition. The viz was <10m. This wreck is entirely covered in netting with oysters everywhere. I did quite a few laps around the wreck in cork screw fashion, working from bottom up to the top (radar etc). On the foresdeck are heaps of tyres and plastic kegs filled with concrete? One open hatch, which looks empty. During the dive I saw Bazza cutting his way through the net on starboard to get inside. I swam around and waited for him to come out on the port side. Obviously nothing of interest inside.
No 2nd dive in the afternoon, as we were chased by 3! thunderstorms. Looks interesting on the radar, until you have a look outside and see the actual clouds. With the waves up to 3m, there was no second dive today.
We had to make a decision today – we could either continue searching rather, or, go back to the “Tottori Maru”. A bit of a gamble, for sure, we decided to continue searching for new wrecks.
Dive #11: 70msw, 94min, DIL: 15/50, SP: 1.30
10 April
The first mark turned out to be a “rubbish wooden wreck”, followed by a mark without a wreck. After that, the 1st dive was on a steel barge. The opinions differ, but I think the barge is lying upside down. In viz of close to 0, I used my reel and attached the line to the anchor line. During the dive I could hear some “clonking” noise and some screeching. As it turned out, the anchor line was tied into what a big anchor on top of the barge. Due to its weight, MV Trident dragged this anchor across the barge until it fell off on one side and dragged along the wreck, leading to my line getting cut. After hitting the wreck during descent, I tried to follow Frits on what I thought was his line, frequently dropping down on my knees to confirm I was still on the wreck. After some time I heard someone cursing and bumped into Bazza, which gave him the fright of his life!
On my way back to what I thought was the anchor line, I messed up my line. At the point where I expected the anchor to be, I found that my line was held in a few coral trees, but no anchor line insight. So I dropped down the side of the wreck and found the makrs from the anchor line being dragged along the wreck. Unfortunately, there were no drag marks in the sand, so I did a blue water ascent in the hope to see the anchor line in the better viz from 36m up. Unfortunately, the deep stop in 38msw (2m below the layer of murky water) screwed up my plans and by the time I got above 36msw, no anchor line was insight … Another blue water ascent. Stupid enough, at 20msw I used my spool (messed up my reel and had lost the closed reel two days earlier) with 15m line, to shoot a bag and naturally got dragged up a few meters by the SMB. The chase boat arrived quickly and waited for me to surface.
Our planned 2nd dive did not happen, as there was no wreck at the mark.
Dive #12: 47msw, 49min, DIL: 15/50, SP: 1.30
11 April
We were looking forward to dive the “Plane wreck”, another one of our marks. Unfortunately, no wreck anywhere. The next mark turned out to be another “rubbish wooden wreck”.
The rest of the day was spent running away from a thunderstorm, during which I spotted my first water spout ever, fortunately in the far distance.
In the evening we arrive at Big Buddha Beach at 6pm. We managed to get UPS to come and take our boxes for shipping back to Sydney. Our last night on board for this trip.
12 April
In the morning I saw another water spout in the far distance through the gap between a small island and Koh Phangan. The it is off to the airport to catch an early plane back to Bangkok.
Wrap up
What a trip!
Three new Japanese Marus, a trawler, a barge and some wooden fishing boats. Great effort, a lot of fun! MV Trident and crew are great hosts and the inaugural “Hammerhead” tour proved to be a very successful trip. I look forward to coming back in 2008.
Thanks Jamie, Stuart, Mick and the rest of the crew!
Some pictures: 
The bow of the MV Trident
Mick (MV Trident crew) getting ready to tie in
The stern of the MV Trident looks like a Rebreather dive shop
On board were: Mk15.5, Meg, Inspiration Vision, Inspiration Classic, KISS Classic
Grub!
Stuart Oehl getting some more beer
Jamie McLeod
Mick - Mini Chef :-)
More Ozzies …Bazza and Steve
Mark is our token Pom
J 
OC diver – Dave’s homebuild was waiting for him to pick it up at Bangkok airport, it never arrived on board for the trip …