By far the most popular diving destinations for Thailand liveaboards is a combination of the Similan Islands and the ‘Northern Sites.’ While one or two boats’ itineraries start in the north and travel south, most start in the south (around Similan Island #5), travel north, and return to the pier in the south again. The reasons that these type of trips are most commonly chosen both by boat operators and divers is simple. They offer the best of everything and easily fit into a 3 Days 3 Nights , 4 Days 4 Nights or 5 Days 5 Nights trip length.
The ‘regular Similan Islands’ is a group of 8-9 uninhabited islands which are ideal for all levels of recreational scuba diver. Although Koh Bon and Koh Tachai are technically within the Similans’ administrative area, most people in the industry regard these two islands to be more connected with Richelieu Rock, in the Surin Islands National Park. Geographically, Koh Bon and Koh Tachai closer to Richelieu Rock as they are to the Similan Islands, and the underwater diving experience of Bon, Tachai and Richelieu is considered to be better than the Similans for experienced divers. Therefore, although technically, Richelieu is alone, most people group it together with Koh Bon and Koh Tachai.
Yes, although they are better enjoyed by divers who can descend to 30m. and are able to handle or dodge a medium current, all of the diving sites can be explored by any certified diver. In any case, all of our boats insist on every diving guest being led by a professional Divemaster guide or Instructor.
As for the best itinerary, although a few boats sometimes start in the north (around the Surin Islands), it makes sense to start in the middle of The Similans and travel north during the cruise. This is mainly because it’s easier to do a ‘check dive’ in the Similans at dive site that can be enjoyed by all levels of diver. Check dives are the first dive of each trip so that the tour leader and Divemasters can properly assess the ability of the diving guests under their care. This is not at all condescending, but purely to ensure that everyone is in the correct diving group to match his or her level of experience, confidence, and air consumption. And another good reason for starting in the south and working your way north is to ‘save the best* to last.’ *Richelieu Rock is the northernmost dive site in the area and regarded by many as the best diving spot in Thailand.
As for trip length, this really depends on the schedule and budget of the diving guests wanting to join, and what’s available. 4D4N trips are the most common, and they allow enough time to explore The Similans, Koh Bon, Koh Tachai, Richelieu Rock and maybe a couple of local shipwrecks on the final day. 4D4N trips have 14-15 dives, which is about the right number for most people. It is no coincidence that the most established dive centres in Khao Lak and Phuket offer 4D4N trips as their main or only options. 3D3N trips are possible to explore both the Similans and the northern sites, but it’s impossible to visit everything in just 10 dives, with usually two at Richelieu, two at Koh Bon and two at Koh Tachai. Of course, the 5D5N trips are even better for visiting all of Thailand’s best diving areas.
Richelieu Rock is part of the Mu Ko Surin National Marine Park, whereas all of the other dive spots are part of the Mu Ko Similan National Marine Park. In addition to a diving fee of 200 THB / day, there is an entry fee to enter each park. This entry fee is currently 500 THB/park and therefore a 4D4N trip that enters both parks incurs a fee for foreigners of 1,800 THB. This is calculated as 2x 500 THB plus 4x 200 THB. 3D3N trips that visit Richelieu Rock incur a 1,600 THB park fee. However, trips that stay within the Similans park only incur the 500 THB entry fee one time. Thai nationals and children pay a reduced entry fee, but the 200 THB/day diving fee is the same for everyone.
In summary, most of the Similan diving liveaboard trips of 3D3N duration or longer will visit the regular Similan Islands, then slowly travel north to Koh Bon, Koh Tachai and finally Richelieu Rock. Then on the way back to Tab Lamu pier, it’s normal for the boats to stop off for the final day’s diving at Koh Bon and/or local wrecks.