Yes, JETSAMS is a Scrabble word!

Letter values in Scrabble US: J 8, E 1, T 1, S 1, A 1, M 3, S 1.

Is it a valid word?

JETSAMS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the part of a ship's equipment or cargo that is thrown overboard to lighten the load in a storm
the floating wreckage of a ship