Rik you nailed it. Cucumaria frondosa. They're usually that end in the sand or even their crevice is in a crevice. But this one in particular had no shame.
Cool! (I figured that even if "rear end of a sea cucumber" wasn't right, it sounded bizarre enough that I could claim I was joking.

)
If I ever get back to BC you'll see some very interesting Parasticophus californicus shots.
Sounds like fun. BTW, I think you meant "Parastichopus" -- Google failed completely on "Parasticophus" and I got to
http://www.racerocks.com/racerock/eco/t ... saraht.htm only by searching on
californicus sea cucumber. BTW, I was fascinated by the video at
http://www.racerocks.com/racerock/archi ... s_16a2.htm, showing escape response. I had no idea that sea cucumbers could move so quickly!
Switching subjects...
I've been pondering your equipment questions. I don't dive, but I do backpack, and there are just enough similarities to make me wonder whether DSLR is really the direction you want to go.
What I've discovered backpacking is that the latest generation of point-and-shoots lets me get more pictures of what I want than my DSLR did. I used to carry into the wilderness my Canon 300D and an extra lens or two. But now, I just strap a Canon A710 on my belt and take off. It's smaller, lighter, more maneuverable, has fairly trustworthy auto-focus even in macro, and the rear-panel display means I don't have to get down on my belly for those low-angle shots. (The latter is most appreciated while carrying a 50-pound pack!)
For a lot of applications, the DSLR is far superior. But for getting good images quickly in uncomfortable conditions, the A710 wins big. See
here and
here for examples of image quality.
I see in some review articles that the A720 (successor to the A710) does have some sort of underwater housing. I have not even seen a picture of it, and I have no clue how well it actually works.
But the tradeoffs are worth considering, anyway.
If you can arrange to borrow or rent equipment to test before buying, then I strongly recommend to do that. I've been surprised enough times to be really nervous about the difference between what I expect and what I actually get.
--Rik