Unidentified Swimming Object... ID, please..?

Photo taken in mid water (Tulamben, Bali, Indonesia) by Pairach Leerungnavarat.

Absolutely no idea what it could be... Help, please?

Nice one, I have no idea either.....

Photo taken in mid water (Tulamben, Bali, Indonesia) by Pairach Leerungnavarat.

Absolutely no idea what it could be... Help, please?

It looks a lot like a salp, but I have neve seen one with a long 'tail' like that.

It's a pelagic snail in the family Carinariidae. There's at least one IP species that has brown pigment along the tail - Carinaria cristata - so it may be that. Pelagic snails are pretty fantastic. Shells are reduced or even absent while bodies are translucent to completely transparent. Usually the only parts visible are the eyes, mouth parts, and stomach areas. They're voracious predators of other pelagic critters such as salps, chaetognaths, and other snails.

http://www.tolweb.org/Carinariidae/28733

http://www.tolweb.org/Carinaria_cristata/28748

http://www.tolweb.org/Cardiapoda_richardi/28745

It looks a lot like a salp, but I have neve seen one with a long 'tail' like that.

I am guessing that it might be a pelagic gastropod (sea snail).

Edit: oops, Leslie beat me to it. Thank you for confirmation