Too bad about your HDD!
Well, I don't think it's a Paracaudina or another sea cucumber. Paracaudina species - especially young individuals - have translucent skin and it's easy to see the 5 muscle bands characteristic of holothuroids. They should be visible in an animal this size. I believe it's probably an acoel worm. They aren't noticed very much because of their small size. Until recently they were classified with flatworms but now they have their own phylum - Acoelomorpha.
Thank you Leslie,
I will look into the acoel worms to see if there are any other similarities and information. It is interesting to know that it is something not too observed due to it's size but when your waiting for a videographer dive buddy and looking around at a single spot, you tend to notice the smallest of things moving on the ground.