Everything ran smoothly with The Multihull Company and we are very pleased with the result. We felt supported and well advised throughout the whole process. Every stage of the purchase (inspection, test sail, survey, rig check etc) was well organised and ran like clockwork.


~ John B. Thornely
Taka Oa


Every step along the way in dealing with you and your company has exceeded our expectations and we cannot thank you enough for the assistance.


~ Jim and Karen Doyle


My advice to anyone buying a catamaran, new or used, is to find a real professional, a true buyer-broker with vast experience and integrity, who understands that counting happy customers is far more important than turning a fast dollar.


~ Andreas Julseth
African Innovation

Bottom Paint Guide Part 1: Anti-fouling Paint and the Marine Environment

Share |

More Editorial by J. Summer Westman
November 2006 Issue

Keeping crud off the bottom of a boat has been a problem for mariners … well, probably since before recorded history. From oil to tar; from tin and copper sheeting to tin- and copper-based paints; and even from chili powder to indelible markers … Boaters have tried everything to keep their boat bot toms smooth and clean. Environmental concerns, however, are forcing mariners to find new ways to protect their boats without poisoning their playground or workplace.

If you are a new owner, you might be wondering why you need bot tom paint. The Caribbean’s warm, salty water provides extreme fouling conditions. If you keep your boat in the water, many marine plants and animals will view the bot tom of your boat as a perfect home. Their attachment to your hull will, at best, slow your boat and, at worst, foul your intake valves and props. Your engines will have to work harder to move your boat, and that green stuff on the bot tom looks yucky.

In the 1960s, chemists developed anti-fouling paints that contained metallic compounds. One in particular, tributyltin, proved particularly effective … So effective that by the 1970s TBT could be found on the hulls of most seagoing vessels. Unfortunately, TBT proved to be toxic to more than just the slimy crud.

Scientists discovered by the mid 1970s that concentrations of TBT as low as half a nanogram (the plastic cap of a Bic pen weighs about one gram: www.wikipedia.org) caused a phenomena known as “imposex” in the female dogwhelk. What is imposex? It is a result of endocrine disruption so severe that females grow a penis and are unable to reproduce. By the early 1980s, French scientists linked declining growth rates of oysters in Arachon Bay to tributyltin. In 1982, France banned the use of anti-fouling paints containing TBT on vessels less than 25 meters in length. 1

According to sources in a report compiled by the International Maritime Organization, Focus on IMO—Anti-fouling systems, by the 1980s, high concentrations of TBT were reported in coastal areas around the world. That report went on to state that “In the open seas and oceanic waters, TBT contamination was seen as less of a problem, though later studies showed evidence of TBT accumulation in fish and mammals.” In case you missed it – that’s “fish” – what we potentially eat … And “mammals” – potentially us. “TBT has been described as the most toxic substance ever deliberately introduced into the marine environment and has been confirmed to be harmful to a range of aquatic organisms, including microalgae, mollusks and crustaceans, fish and some invertebrates.” 2

Many countries, including Japan, United Kingdom, United States, New Zealand, Australia and Norway, followed France’s lead, strictly regulating the use of, and/or banning the production of, anti-fouling paints that contain TBT.

The International Convention on the Control of Harmful Anti-fouling Systems on Ships was adopted on October 5, 2001. The Convention’s purpose is to prohibit and/or restrict the use of harmful anti-fouling systems worldwide. The Convention contains an Annex that specifically prohibits the use of organotins compounds (TBT) in those systems. As of June, 2006, the Anti-Fouling Convention, which will only go into force 12 months after ratification by 25 States, had been ratified by only 16 countries. 3

It is up to the individual boat owner to be aware of the impact his or her activities have on the environment. If we are careful, commercial and pleasure boaters should be able to enjoy the beauty of the world’s oceans and its denizens without destroying them.

For further research, please see www.imo.org; www.imo.org/includes/blastDataOnly.asp/data_id%3D7986/fouling2003.pdf; http://www.comnap.aq/publications/conmapatcm/2006_29atcm_ip082-h; http://extoxnet.orst.edu/pips/tributyl.htm; and www.sciencedirect.com – various articles.

Next month: Does the type of boating you do affect the type of bot tom paint you need?

1 The Science and Environment Bulletin, July/August 1998 http://www.ec.gc.ca/science/sandejulaug/article4_e.html

2 2006 – 29ATCM-IP082: The use of Anti-fouling Biocide Paints by National Antarctic Program Vessels (html)

3 http://www.imo.org: Anti-fouling systems

J. Summer Westman lives in St. Thomas, USVI, with her husband, Bill. When not out on their boat, Excellent Adventure, Summer writes boating articles and designs websites. Reach her at summervi@earthlink.net or www.livingbydesignvi.com.


All at Sea

This article was taken with permission from All at Sea
All at Sea – The Caribbean’s Waterfront Magazine is published monthly.

Website: www.allatsea.net
Phone: 443.321.3797


Testimonials From Satisfied Customers


These are stand up people, who make a stand up product. I would buy from them again in a heartbeat.


~ Jay Clark, Dolphin 460
"Sugar Shack"


I just wanted you to know that your level of service and the high degree of customer satisfaction have made owning my Dolphin a great experience.


~ Daniel Zlotnick, Dolphin
"Sugar Shack"

Want to Learn More?

Subscribe to Our Email Newsletter