There are two parts to the fob, the active electronics part ( the batteries and circuit board ) that works to lock and unlock remotely. Then there is the passive 'RFID' chip which is un-powered.
The SKREEM and ring around the key socket excites the chip via RF, then looks at the resulting RF response. It enables start if what it sees is correct.
This 'RFID' chip is nothing but a piece of crystal, so the salt water did not effect it's function, however the circuit board is most likely toast.
You will need to get a new fob from Rob at NeedsWings if you want the remote to work.
( about $160 )