South Siam 4

Similan and Richelieu Rock liveaboard

South Siam 4 liveaboard and speedboat

South Siam 4

  • 2 day 1 night Similan Islands / Koh Bon
  • 3 day 2 night Richelieu Rock, Koh Bon, Koh Tachai and Similan Islands.

South Siam 4 liveaboard (MV Somboon 4) stays out at the Similan islands all season (mid Oct to early May).

Divers are transferred from Khao Lak to the liveaboard by speedboat five times per week. Land transfers to the pier at Khao Lak are also provided from hotels in Phuket.

The dive boat does a weekly loop of all the dive sites including Koh Bon, Koh Tachai and Richelieu Rock. The flexible schedule lets you fit diving around your other travel plans. You can get a lot of dives in a short time. It’s a good value Richelieu Rock liveaboard for the 3 day 2 night trip.

Unlike other liveaboards South Siam also takes day trip divers. (Day divers can join at the Similan and Koh Bon but not at Richelieu Rock). This can make the boat busy during the day but the program is efficiently run and the day trippers have all departed by 3 pm.

Peak season holidays like Christmas, New Year and Chinese New year are busiest (you need to book early for these dates). Because of all the comings and goings and the moving between islands there are fewer beach excursions on a South Siam liveaboard than on other boats.

Read verified diver reviews for South Siam liveaboard below.



South Siam 4 deck plan

  • Sleeps 24 guests in double and twin bed cabins
  • Length 28 metres, beam 6.5m
  • All cabins are air conditioned
  • Shared bathrooms
  • Cruising speed of 10 knots
  • Large sun deck and large shaded deck
  • Tasty and plentiful Thai and international food
  • PADI Advanced courses taught on board


South Siam 4 price


2 days 1 nights (7 dives) at the Similan Islands

  • Double bed or twin share cabin: 13,900 baht per diver / 9,900 baht per non diver
    Mon-Tues or Thurs-Fri or Fri-Sat. Depart morning, return next day evening

3 days 2 nights (11 dives) at the Similan Islands, Koh Bon, Koh Tachai and Richelieu Rock

  • Double bed or twin share cabin: 22,900 baht per diver
    Tuesday to Thursday or Saturday to Monday

4 days 3 nights (15 dives) at the Similan Islands, Koh Bon, Koh Tachai and Richelieu Rock

  • Double bed or twin share cabin: 26,900 baht per diver
    Friday to Monday or Monday to Thursday

Price includes: Dive guide, tanks, weights & belt, all meals, drinking water, tea, coffee, soft drinks, return hotel transfers from Phuket main beaches (Patong, Kata, Karon) and central Khao Lak (Nangthong, Bangniang).

Price excludes: Equipment rental (500 baht per set per day), alcoholic drinks, towels, marine park fees, outside area transfers.

Note: Divers must be advanced certified (or equivalent experience) with dives logged within the last year. The PADI Advanced course can be completed on board for 8,500 baht. Or you can dive with a private divemaster (extra charge of 2,000 baht per day).

Schedule & Itinerary

South Siam 4 itinerary and schedule

  • Departs every morning except Wednesday and Sunday.
  • Returns every evening except Wednesday and Sunday.

Basically you can join South Siam 4 any day except Wednesday and Sunday. You can depart the boat any day except Wednesday and Sunday.

If you want to dive Richelieu Rock, schedule a Wednesday or Sunday into your trip.

On the first day you will be collected from your hotel in Phuket or Khao Lak in the morning (6.00 am-7.30 am depending on your hotel) and transferred by minibus to Tap Lamu Pier. From there you will be transferred by speedboat to the South Siam 4 liveaboard.

On the last day you will be transferred off South Siam 4 in the afternoon and arrive back at your hotel in the evening.

Book / Enquiry

Online booking

Don't like forms?
Hotline: +66 81 2727556

  1. Tell us the dates you are interested in. We’ll check available options and provide you with a clear breakdown of prices.
  2. When you are ready to go ahead and book we’ll reserve your place(s) and email you the secure online payment instructions.
  3. 10% deposit to confirm your booking. Payment is online by credit card or paypal (no booking fee or credit card fee), or by bank transfer.
  4. Balance payable 60 days before the trip departure date.

Payment method

project aware

South Siam 4 reviews

Best price for South Siam 4 Overall rating: 4.5 out of 5 based on 2 reviews.

South Siam 4

4 5 1
the trip was really very nice! We had three fantastic days of diving, nice food on the boat and the crew was really outstanding - they really took care of everything, didn't expect them to take care of the gear even. I didn't take any pictures myself but our guide Greg Hanigan took some great shots: The only not that great experience was that when we arrived at the office after the bus transfer to Khao Lak, the guy wanted us to pay around 2000 Bhat more than my own calculation. And I included all the rentals, natural park fees, etc. In the end we kind of agreed that it must have been the deposit that he got wrong. But that was also hard to tell because he didn't have a proper breakdown but just a few numbers scribbled down which came out at 2000 Baht more. Also, the lady that paid right before us had the same issue. Despite this little inconvenience our trip was amazing and I can only recommend the South Siam 4 and Thailand Liveaboards. By the way, have you been on board of one of these boats as well?

South Siam 4

5 5 1
Dear Paul, Similan trip is marvelous. The staff on SS4 is friendly, the DM is knowledgeable. Really enjoy the dives in Richelieu Rock. Cheers, Siew

Hello Paul, Just a belated note to thank you for sorting out this Koh Bon trip for us, it was another excellent day of diving and we saw a giant manta ray, which was just blinking awesome! Back in cold England at miserable work. Oh well, it was a great holiday! Best wishes, Jess

This post is also available in: Italian Thai

This post is also available in: Italian Thai