Mooring Lines – “the property of all becomes the responsibility of none”

One of the most readily observable, and avoidable, damages to coral reefs is due to the dropping of anchors to park boats. Dropping an anchor instead of using mooring lines can destroy hundreds of years of coral growth in only a few moments, and leave a pile of unconsolidated rubble in its wake which can take decades or centuries to recover. Mooring lines are permanent lines attached to a solid base that boats can pick-up and attach to, rather than dropping anchors on or near the reef.

On Koh Tao, we have mooring lines at every dive site around the island, which not only allow boats to park but also improves the safety of divers ascending and descending.  In all, there are over 130 mooring lines around the island as of late 2014. But this was not always the case. In 1998, only 3 of the island’s then 19 dive sites had mooring lines, and boats dropping anchors on the reef was identified by survey respondents as the most “prominent and visible impact” to Koh Tao’s reefs (Flumerfelt, 1999). Furthermore, many instructors on the island at the time told numerous stories of being almost hit by falling anchors while teaching courses to new students. The major problem, they said, with installing mooring lines was the cost, the lack of involvement by the island’s then 18 dive schools, and a lack of understanding about the maintenance involved.

Mooring lines need constant inspections and maintenance, and no matter how well designed they are, all will eventually break. The local cost of a mooring line is about 10,000-20,000 THB, so it is also not easy to get dive schools to help front the money. The problem is made even worse by that fact that usually only a few dive schools will pitch in, then they will be upset when they see the non-contributing dive centers (‘free-riders’) using the mooring lines. This give those contributing dive schools less incentive to repeat the work in the future, and creates animosity between local businesses.

Luckily, on Koh Tao the government and dive community have increased their cooperation and capacity greatly since 1999, addressing the issue comprehensively starting in 2008 with the creation of the local community group, the Save Koh Tao Marine Branch.

Over 2008-2010, many of the mooring lines around the island were replaced or removed, and new mooring lines with more appropriate bases (large rocks, large non-living coral heads, etc.) were added. Over those years, several community meetings were held, the dive industry representatives marked out on maps where new buoys were needed, and the DMCR provided training and the materials which the island could not afford. Of course not all dive schools helped out, but about 9-12 dive schools (of the then 48 on the island) put in enough effort to ensure that most sites had buoys most of the time. Additionally, “no boat” areas were designated in several locations around the island with yellow buoy lines to protect the shallow reefs and also provide a mooring point for small crafts like longtail boats.

But, as the dive industry on Koh Tao continues to grow, the mooring lines which used to be sufficient are no longer adequate. Boats on Koh Tao have become much bigger, with some dive schools now having boats with a capacity of over 80 divers. Additionally, the number of boats visiting a site at any given time can exceed the available mooring lines, leading to breakage of the lines or boats dropping anchors.

Then, in 2012 the project really took off, after Ajarn Sakanan Platong of the Prince of Songkla University took an interest in managing the issue around the island. He helped to increase the amount of mooring lines materials sent to the island every year by the DMCR and the Marine Fisheries Department by urging them to take more action on the issue. Then, in 2013, he helped to get the oil companies operating in the Gulf of Thailand (Chevron, PTT, and Salamander) to donate the money necessary to bring 45 large concrete blocks (12 tons each) and 140 Artificial Reef Cubes to the island to add additional mooring lines in the areas of need. The sites for the blocks were again chosen by the participating dive community, and then the lines were installed by a handful of participating dive schools, primarily New Heaven and Crystal Divers.

The blocks work great for the larger boats on the island, are easy to locate and repair, and will last for decades. However, for installation they are dropped from a very large barge, and for environmental and safety reasons must be dropped away from coral reefs. This is generally fine for divers, as it gives the students a bit of time to regain their buoyancy control over a short swim before entering the reef, but is not ideal for snorkel and tour boats.

Later, in 2013 and again in 2014, the DMCR added around 60 smaller blocks (5-6 tons) close or in the coral reef areas to provide mooring bases for the longtails and smaller crafts, and special white and blue mooring balls to designate them.  This is still very tricky, and although little damage was observed, dropping concrete blocks in coral reef areas is not ideal.

So, in 2014 Ajarn Sakanan initiated another project to design a mooring line base that would be heavy and sturdy, but could be transported in smaller pieces by divers and then assembled underwater. This design allows diving teams to strategically place moorings in shallow coral reef areas with minimal impact to the environment. In May of 2014, two experimental units were placed down at a shallow reef area near Freedom Beach (see the video of that project here). After a 6 month evaluation 30 more units were sent to the island, funded by Chevron and the DMCR. As of Late 2014, most of the units remain to be installed, but over the coming months our team at the NHRCP will be working hard to get them in place, hopefully with the help of other dive schools.

Mooring lines are a vital tool in conserving coral reefs wherever boat traffic is found. But, they are also a difficult project to undertake due to the high on-going costs and maintenance time. It is truly a full time job to keep the 130+ mooring lines around Koh Tao in working order. Yet, although all of the dive and snorkel boats need and use mooring lines on a daily basis, few understand the amount of time and effort that goes into making sure they are always there. As with many other public goods, everybody feels entitled to using them and “the property of all becomes the responsibility of none.”

So, whose job is it to maintain all of the moorings around the island? For years we tried through the Save Koh Tao group to involve local dive instructors and staff in the methods and techniques, training over 160 people in free workshops conducted over 2011-2014. Sadly only a very small handful of them ever assisted in the installation or maintenance of the moorings around the island, choosing instead to receive the free training for their CV and shop Facebook page, without contributing back for the good of the island.

This year, the NRHCP is continuing own mooring line efforts, using our own resources to dedicate at least 5 days a month solely to their repair around the island. We will also be providing training for other instructors around the island, providing that they actually go out and do the work through their own dive school after receiving the training. If you would like to get involved, contact us at This email address is being protected from spambots. You need JavaScript enabled to view it. for more information.


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Phone: +66 (0)77 457045 or + 66 (0)91 8324800
48 Moo 3 Chalok Baan Kao
Koh Tao, Surat Thani
84360 Thailand

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