What is this amazing bottom-fouling seaweed called?

[foojin]

Friends sailed home from Japan to the Salish Sea a few years ago in their cat. Their hulls fouled with some sort of seaweed and about half way home they had to scrap the bottom before they could sail on.

The next year I followed them. The day before I left from a marina near Osaka I scrapped the bottom clean. But within a couple of weeks, we started to slow... slowing to a crawl. Same problem.

Bottom was covered with amazing growth. Took four hours over three cold dives over several days (in water miles deep over the Mariana Trench) for me to scrap the bottom (Vancouver 27). Once removed, it never returned.

Sorry, no pictures

It is like fat, little fingers that grow in bunches. There texture is like succulent plants. Pinkish green is the color I remember. You really have to scrape to get them off. Tenacious little buggers. Hard, cold work. Wished I had a wet suit.

Any ideas about what this is called? I've been asked to give a talk and it was a big issue for me on the crossing. Have been googling like mad with little luck.

[StuM]

Green Sea Fingers aka Dead man's Fingers?

Invasion Biology Introduced Species Summary Project - Columbia University - Dead Man's Fingers

Native to seas around Japan but are now an invasive species worldwide - mainly as a result of being transported on hulls

[foojin]

Thanks Stu, underway at the moment, but will follow your link as soon as I can.

[zeehag]

i practice the fine art of having my hull scraped before each passage so i donot transport invasive species indiginous to the locales i cruise.
makes a difference on my alleged speed as well-- there is a big difference between 2 kts and 4 kts......

[foojin]

Back home now Stu and followed the link. I'm sure that's it. You're brilliant. Much appreciated.