[Coral-List] Underwater signage follow-on

Michael Risk riskmj at mcmaster.ca
Tue May 21 09:12:24 EDT 2013

Good day, all.

We really have to stop meeting like this-I have work to do. Nonetheless, at my age one forgets stuff, and it occurred to me that something from the past may be useful here.

Many years ago, when I had the project in Indonesia, my friend Cam Lewis (whose work will be known to gorgonian people) became intrigued by the fact that the bases of soft corals were never bored. This, in some of the most "bioactive" water on the planet, north coast of Central Java, a place where unprotected wooden boats, usually made from teak, lasted only a few months. If constantly maintained and painted with evil stuff, they lasted maybe a year. We were concerned about all those teak trees, and the fact that, for the fishermen (relax, PC people-in Indonesia, they are ALL men), the boat was their largest investment-larger than their houses. 

We began investigating the mystery of why the soft corals were not bored. In a burst of intelligence atypical for me, I brought in a young Indonesian, Ocky Radjasa, to do grad work at McMaster on this. (Ocky turned out to be a brilliant young scientist who now runs his own institute on Java, researching bioactive marine compounds and interacting internationally.)

To summarize about 5 years of field testing and lab work, it turns out soft corals secrete cetyl palmitate, which inhibits biofilm formation (esp. Vibrio) on submerged surfaces, and shortcuts larval settling. CP is safe for people (a major component in stuff like hand creams) and volume/volume costs less than the beer I drink.

We played around with formulations: if you mix too much CP into paint, the paint slides off, duh…turns out about 1% is OK. This amount, mixed into ordinary housepaint, protected fishing boats better than the going antifouling paints-which are highly toxic.

I acquired some sort of preliminary patent protection and then donated all the rights to the university in Indonesia, UNDIP. That's the last I heard of the whole thing. But it now occurs to me that a small amount of CP mixed into a gelcoat covering some signage couldn't hurt, and could help a great deal.

(For some freshwater coverage: CP also retards Zebra Mussel settling.)


On 2013-05-17, at 1:48 PM, Michael Risk wrote:

> Good day.
> Many years ago [the statute of limitations has now run out] I was attempting to obtain settling rates of invertebrates on panels with different textures, set underwater at Catalina Island. I ran into terrible problems with treasure hunters/vandals/thieves damaging the experimental setups. So I devised a modified technique. I wrote my text on the panels using red nail polish, and then covered that with a fiberglass gelcoat. The panels themselves were simply soft wood 2 x 6 pieces, covered in fiberglass. What I wrote was not accurate, but was designed to repel invaders.
> Worked like a charm. The panels were underwater for many months, the signage remained legible, and any algae could simply be wiped off.
> A friend of mine, the manager of the Marine Lab, was standing on the lab dock one day when a dive boat pulled up, and a red-faced overweight  irate diver  jumped off. He said "Hey! I was just diving out on the rocks, and I saw some panels down there.  I whipped out my knife and was going to collect them for my rec room, when I read the sign that said DANGER RADIOACTIVE.  Am I in any danger because I came so close?"
> Bob had a moment to think, this is the kind of guy that has just caused Mike to lose six months work. Then he said "Sir, you are in absolutely no danger. There is only a slight chance of any damage. Go home, and if you do not notice any change in your external genitalia over the next six months, you will know you are out of danger."
> Several lessons here. First, don't try this at home. Second, a gelcoat over your text is a guarantee of longevity. Of your text.
> Mike
> On 2013-05-16, at 8:39 AM, Ruleo Camacho wrote:
>> Good Day,
>> I am attempting to create some underwater signage for a snorkeling reef
>> trail but I have been having immense difficulty in obtaining a material
>> which would be adequate to stand up to the rigors of salt water and and
>> micro organisms. Any suggestions on what materials/methods may be suitable
>> for this use?
>> Regards
>> -- 
>> Ruleo
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>> Coral-List at coral.aoml.noaa.gov
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> Michael Risk
> riskmj at mcmaster.ca
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Michael Risk
riskmj at mcmaster.ca

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