The Scintillating Similans

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The boundaries of the Andaman Sea are the Bay of Bengal, Myanmar (Burma) to the north, Thailand to the east, and continued southward, these waters narrow to the Straits of Mallaca. For many centuries, this Sea has served the peoples and economies of the region for transport, dredge mining, providing fisheries to support burgeoning populations, and offering popular tourist destinations; especially the beaches and limestone islands of the west coast of Thailand. Large populations adjoin with at least 118 million (year 2009) residents of Myanmar and Thailand alone. Understandably there is growing pressure on the Sea’s resources for potentially conflicting purposes. The glossy brochures told us of Mantas, Whale Sharks, and Leopard Sharks. We were eager to see the rare Yellow Seahorse (of no food value, its existence is endangered by adjacent nations that consume some 16 million Seahorse annually!) You must explore these waters and their Koh Similan National Park now, before their special character is lost to future generations.

Getting there. Fly in a day from major Australian cities to Phuket, then mini bus to Patong which is about an hour south. Flying business class on Singapore Airlines with a short transit through Singapore you are, as a gourmet traveller, well prepared with fine cuisine and Bollinger to survive the week ahead; in economy, they give you by arrangement 40kg weight allowance (but no Bolly!). At Patong, we stayed at the Royal Phawadee Village which was comfortable with friendly Thai hospitality; it features air conditioned villas set amidst orchid gardens and a refreshing swimming pool; a welcome change when you are “shopped out” from the hustle and bustle of the streets of Patong. Accommodation was about A$115 per night with our Allways divers discount, and they link with Mermaid Dive. No dieting on this trip… as we commenced with a meet and greet welcome dinner, and the next morning a lavish smorgasbord breakfast. Be sure to try the Dragon Fruit.

Day boats operate to the Similan Islands from adjacent coastal communities (83 dive boats at least) but the best way to do it is with an experienced live aboard operator. The Mermaid fleet is based in Katong. With over ten years experience in the area, they are the East Indian Ocean specialists, and range from the Andaman sea up into Burmese and Indian waters. The Burma Banks have in the past been a prolific dive site but no longer, as they have been dredged to desolation and unfortunately, they are no longer visited by Mermaid. Our team of rambunctious Aussies (with one Kiwi) was ably managed by our unflappable Swedish divemaster “PJ” and John, the laconic English dive guide. Cassandra, the ever pleasant French Canadian, chaperoned the French-speaking members on the trip.

Our luxury live aboard, Mermaid 1 (of three boats in the Mermaid fleet), was very comfortable, with camera table on the dive deck, nitrox, and clean air conditioned cabins with en suite. The warm towels after a dive were a real treat as was the Thai massage. Three sumptuous meals were provided daily with snacks between dives and complimentary soft drinks. PJ’s dive briefs were comprehensive accompanied by white-board diagrams. With up to four dives a day it was a busy time for all. The “boat boys” were always attentive and helpful, especially to our over 70s members…a new demographic on live aboards! Just a note to the wise, they provide rentals and nitrox priced in Euros but billed in Thai Baht – so to avoid a 3 percent surcharge as well as double exchange conversion on your credit card, take Euro cash to pay for your incidentals on the boat.

Our custom designed Thai Safari took us first west to Anita’s reef, Elephant Rock, North Point on Island Number 9 of the Similans; then we steamed offshore to Koh Bon Pinnacle, and Koh Bon West Ridge. A shore stop at Donald Duck Bay, Ao Guerk, allowed us to stretch our legs with a walk up to Sail Rock (which looks like Donald Duck’s head I’m told). In this picturesque bay, a turtle (the only one I saw) appeared for its afternoon banana. Isolated pinnacles with their concentrations of marine life are a feature of the aquatic terrain. We dived Koh Ta Chai Pinnacle, then Koh Ta Chai reef for the night dive, and on day 3 the remote Richelieu Rock about 10 km from Burma waters. Here we counted 12 dive boats, but they left during the afternoon, which allowed us “sole use” for the night dive. PJ had designed our itinerary to lessen the overlap with other dive boats. We steamed back to Koh Bon pinnacle and again Koh Bon West Ridge. From here we turned southward and voyaged to the wreck of the “Boonsung” a tin mining dredge sunk over 30 years ago, and broken up further in the Tsunami of Boxing Day, 2004. Closer to the coast, you will see large areas of barren coral which apparently have been bleached due to sea temperature rise following El Nino events, but further out from land there are signs of active regeneration of both hard and soft corals. Overnight we steamed to Hin Daeng and Hin Muang, with the night dive to see the feeding Morays. On the last day, after an early arrival at the Koh Ha chimney, and the Koh Ha caves, we went onto Bida Nok in company with other dive boats, and Bid Nee to dive a lovely wall in strong current. On the last evening, we moored in Phi Phi Island and took our R & R amongst the bars and bazaars of Phi Phi.

There were numerous underwater highlights and I offer my favourites. “Boonsung” on an eerie dusk dive in a monsoonal downpour saw flashes of lightning added to those of the photographers’. Two Stonefish (Synanceia verrucosa) were nearly invisible in the murk of the silty bottom, Spotfin Lionfish (Pterosis antennata) if not swirling around looking for a feed, were lined up with retracted fins lying along the wreck as if to sleep, and the striking Zebra Moray (Gymnomuraena zebra) was seen nestled next to banded Coral Shrimp (Stenopus hispidus). On this dive, we found the rare Nudibranch Kanga Hypselodoris (Hypselodoris kanga) to the delight of PJ who has been looking for it for ten years!

As a “macro tragic”, I include some images of colourful non nudibranch, Mobius’ Thuridilla (Thuridilla moebii); and, Nudibranchs. Phyllidia were most prevalent: Celestial Phyllidia (Phyllidia coelestis), Elegant Phyllidia (Phyllidia elegans), and the Ocellate Phyllidia (Phyllidia ocelata). Also, Strickland’s Halgerda (Halgberda stricklandi), Tessellated Halgerda (Halgerda tessellata), Ornate Dermatobranchus (Dermatobranchus ornatus), Wedding Cake Nudibranch (Dermatobranchus gonatophora), and the Caramel Hypselodoris (Hypselodoris maculosa).

Richeliu Shoals, a magnificent dive site, showed us the Yellow Seahorse (Hippocampus histrix), Tigertail Seahorse (Hippocampus comes), and fantastic Decorator Crabs (Cyclocoeloma tuberculata) and Sponge Crab (Dromia dormia) on the night dive. Troops of the Durban Dancing Shrimp (Rhynchocinetes durbanensis) timed-shared rock crevasses with Urchins, and Eels.

Many colourful Angel Fish and Butterflyfish were encountered at all the dive sites, including the Racoon Butterflyfish (Chaetodon lunula), Black Pyramid Butterflyfish (Hemitaurichthys zoster), Moonbeam Dwarf Angelfish (Centropyge flavipectoralis), Red Tailed Butterflyfish (Chaetodon collare) and the vivid Blue Ringed Angelfish (Pomacanthus annularis). On more coastal dives, the fish population was not as dense, but we enjoyed currents, caves, and swim thrus in the limestone islands often with gardens of pastel coloured soft corals.

Hin Daeng yielded a large Octopus (Octopus vulgaris) and the ornate Ghost Pipefish (Solenostomus paradoxus). Our night dive at Hin Daeng was a macabre spectacle of aggressive feeding Moray Eels emphasizing the beauty as well as the danger of the underwater world. I wonder with the paucity of sharks whether there is a re-shuffling in biodiversity with now a proliferation of the Moray Eel as dominant nocturnal predator.

The overall most outstanding experience was our encounter at Kon Ton Pinnacle with a sole female Manta Ray (Manta birostris) who kept us enthralled for over an hour with majestic acrobatics, sweeping just above the excited divers, which in 25m viz was an unforgettable experience!

Sadly, only one shark was seen during the week. The Leopard Sharks (Stegostoma fasciatum) and Whale Sharks (Rhincodon typus) that helped to make this area famous with divers were not to be seen–fins of that gentle giant command US $20,000 in certain markets. The effects of competing pressures on this prolific marine environment were frequently discussed; at the end of the monsoon season, the dive operators cut drag nets off the pinnacles. According to UN studies, there are declining catches of fish and crustaceans. We saw, after the National Park’s patrol boat left the Richelieu shoals at dusk, the lights of an encircling ring of trawlers approaching during the night.

The Andaman Sea and its dive sites of the Koh Similan National Park remain among the great dive locations of our world, accessible, with diverse marine life, however they remain under severe pressure, so my advice, is pack your bags and go soon while they are still special!

By Dr. Roger Welch.

Useful references:

Coleman, Neville, “Nudibranchs Encyclopedia”, Neville Coleman’s Underwater Geographic Pty Ltd., 2008.

Debelius, Helmut, “Indian Ocean Reef Guide”, Ikan Unterwasserarchiv., 1997.

Debelius, Helmut, “Crustacea Guide of the World”,  Ikan Unterwasserarchiv, 2001.

Mora, Chutinan et. al. “Similan, Pocket Dive Site”, Vacation and Design Co. Ltd., 2006

Panjarat, Sampan, “Sustainable fisheries in the Andaman Sea coast of Thailand”, Division for ocean affairs and the law of the sea office of legal affairs, the United Nations, New York, 2008.

Widestrand, P.J., “Diving in Thailand” and “Mermaid Liveaboards”, films.

Dive Travel: Allways Dive Adventures, Melbourne, Australia.

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