Ship worms

[Phillip Allen]

What's known about ship worms and when do they become a problem? What geography?

[RGM]

"When do shipworms become a problem?" Long before you are aware of them. Sorry, I don't mean to sound like a smart ass. Shipworms are available in a few different species, Toredo and Bankia, each of those apparently has sub-species also. There are other "marine borers" that aren't considered shipworms but will still chew away at your boat just as well. Anyway, shipworms like salt and/or brackish water, probably the warmer the better, they don't like creosote or coal tar compounds. They aren't fond of copper bottom paint or Irish felt. You'll find them everywhere, perhaps a little less common in the colder waters of the Northern latitudes. But that is where some of the other marine borers are comfy. Shipworms and marine borers in general start life as free floating little critters. They attach themselves to underwater hull structure when they're very small and soon evolve into the boring, ravenous creatures that eat away at our boats. They tend to honeycomb whatever they are chewing on and living in. Some shipworms can grow up to about 4' in length. I believe that they remain anchored at the point where they originally bore into the wood and that they grow in length and perhaps diameter from there.

[Andrew Craig-Bennett]

Thee big worms like teredo navalis (there's a name that tells a story!) don't care for fresh water. But some other timber eaters, such as the gribble, a little shrimp type critter we have in NW Europe, absolutely love brackish water.

[cap'n Ron]

When Patience lived in Miami,Fl.
she was refurbished every year at Summerfields Boat Yard on New River in Ft.Lauderdale, Fl. John Lee,yard manager" advised me to have the bottom "steel flexed" to prevent teredo worms from doing their dirty work. Steel flexing is applying a type of epoxy to the bottom. He further advised me that they dont usually adhere unless you are sitting in the mud. He's a very friendly guy and will be happy to answer any questions you may have.
Cap'n Ron