Sharkfin Deep Drop is the second deepest technical diving site in the Gulf of Thailand, reaching depths of 85m. Although it is in close proximity to the Samaesan Hole it has much marine life with fewer hazards
SHARKFIN DEEP DROP DIVE SITE LOCATION
Sharkfin Deep Drop (AKA Samaeasan Cliff) is located in the Gulf of Thailand, Koh Samaesan, in Sattahip District, Chonburi Province. It lies South West of Sharkfin Point (Hin Lak Bet).
SHARKFIN DEEP DROP HISTORY
The dive site is one of the deepest in the Gulf of Thailand at 85m, only exceeded by the adjacent Samaesan Hole. Local marine charts state that this drops to 96m but we have not found this to be the case from our dives.
ABOUT SHARKFIN DEEP DROP
As the name implies, this dive site features a steep, overhanging cliff (the drop) beginning at 50 meters and descending to 85 meters. This makes it the second deepest technical dive site in the Gulf of Thailand. Like its neighbour, the Samaesan Hole, visibility is limited; therefore, torches are required for exploring below 50m. However, unlike the Samaesan Hole, this site does not present significant hazards such as strong, unpredictable currents or the presence of explosives or ships, making it well-suited for Advanced Trimix training dives.
Marine life in the area is noteworthy, which attracts local fishing vessels to the vicinity. Species commonly observed include grouper, barracuda, devil rays, and bull sharks that can found amongst the barrel and whip corals. Due to the size of the dive site I would strongly recommend a DPV to get the most out of this fantastic dives site.
Sharkfin Deep Drop – Hazards
- Depth: Sharkin Deep Drop descends down to 85m at its deepest part. Hypoxic Trimix is therefore a recommendation for most divers. At these depths, deep air divers will have potentially debilitating nitrogen narcosis to manage as well as closely having to closely monitor for Ox Tox.
- Visibility: Be prepared for poor visibility (3-10m) throughout the dive.
- Darkness: Light does not typically reach below 60m at this site. Although in certain conditions this can be experienced as shallow as 30m! At the deepest parts the water is an inky black, with turbidity limiting whatever reach your primary light has. Bring a back up torch!
- Strong Currents: The area has strong currents, so check the tides times before you go as there are only few days each month where tidal conditions (on paper) are ideal. Currents are not as strong or as unpredictable as at Samaesan Hole, so it is possible to dive here if you miss slack tide. Ensure that you have a vigilant boat captain that will look out for and follow your DSMBs otherwise there is a very really chance you will be lost at sea.
- Down Currents: The strong currents do not just push you along – they will also pull you down. So watch your depth and ascent/descent to make sure you do not overshoot your planned depth or are getting dragged back down during your ascent. If during the dive the water suddenly becomes murky it is generally advised to start your ascent immediately. Ensure a wing with sufficient lift and that you have redundancy.
HOW TO DIVE AT SHARKFIN DEEP DROP
The site is only accessible by boat, which is roughly a 40min trip from Chong Samaesan where most of the dive operators moor their boats. Dive operators for this site are typically based in Pattaya so if you are wanting to dive here then this is a good starting point for finding shops.
Due to the number of hazards associated with this site I would strongly recommend an experienced operator and Technical Dive Guide/Instructor who is very familiar with local conditions. I would highly recommend Dive Pattaya and Tec Pattaya for this due to them having a dedicated tech diving boat; gas blending & equipment maintenance facilities; and experienced TDI, PSAI and PADI Tec Instructors who regularly dive this site.
Best Time of Year to Dive Sharkfin Deep Drop
The technical dive season in the Gulf of Thailand is typically from November to April. Weather is typically cooler and calmer leading to improved sea conditions and better visibility (up to 20m). This coincides with the high tourist season so hotels and flights may be a bit more expensive. Whilst the Sharkfin Deep Drop can be dived all year round, in the low tourist season (May to Oct) weather conditions can be unpredictable. The seasonal monsoons bring wind and rain which ultimately means increased waves and poor visibility. You may be able to get a good deal on flights and hotels during this season but your dives may be cancelled or impacted. Just factor this in when deciding to go.
Optimal tidal conditions for diving Sharkfin Deep Drop
As well as seasonal variations it is also recommended to check local tidal conditions (Sattahip Buoy). There are typically 3-6 optimal dive days a month during Neap Tides where divers can get plenty of slack tide to dive in. Factor this in when planning your dive trip. The images below should clearly highlight which day is best to go diving! The site is still diveable under poor tidal conditions (I dived 22 April 2026!)
