Did someone mention me? What a memory you have Leslie.

Yes, I photographed a similar Nemertean Worm at a site called "New Guinea", St Vincent on 3rd Nov 2007. Click Here at 15 metres
I didn't know what is was at the time but Leslie on another board (I dare not speak it's name
) kindly identified it for me.
btw. Don't Ned & Paul always dive with Bill over at Dive St Vincent, though I guess they could have got fed up with the lack of rinse facilities and wandered over to Indigo. I know I will next time. 
Brian,
Yes Ned and Paul are diving with Bill, but I popped in to Young Island to say 'Hi!' and to introduce myself! They are here with a very big REEF tour (2 weeks 50 divers). Bill has the boats for the big groups, I prefer small groups and intimate diving experiences....
...plus I'm better looking than Bill! lol!
I saw this little fella whilst on a critter hunt (which included bat fish, porcelain crabs, frog fish etc....). It's really great when you find something that you haven't seen before... and this was special even by St. Vincent standards!
Stopped and watched it for quite a while, not scared, the worm just went about it's business... pretty cool.
Looking forward to diving with you the next time you re down this way.
No, for the Nemertinator...

Tubulanus rhabdotus (Nemertea), nothing specific known about feeding but probably a predator and scavenger. Perfect desription of its head movement. However, skin is fully ciliated but covered in mucus that it probably makes sticky when handled. What is location of find please? Any data on size? Thanks.
Location: St. Vincent, leeward coast, dive site 'Over There'
Animal size about the same as a length / thickness of angel hair pasta when animal is 'extended'.
Depth seen approx 10 metres / 30 feet.
Hope this helps.
Is this a very rare worm? What is its range? Very curious to find out more info too!