@PBD WD40 might be your friend on the boat but not on my ski. The new hardshell systems have galvanized or painted steel parts such as buckles and release mechanisms, wd40 will eat the top layer and expose the metal to the elements quicker. Silicon spray and silicon grease is definitely your friend.
If you want to unscrew a rusted Silvretta release then yes WD40 is your friend.
Fin clamps and other aluminum parts that use stainless screws suffer from electrolysis and the thing is to use grease or silicon grease (before using it on any kind of water) to create a film layer between aluminum and stainless steel.
Try to use silicon based products, they are not petroleum based and they do not harm rubber or plastic.
Best thing is to use these from when ski is new and after any use. Your ski will look great with no rust or stack screws and adjusting fin or bindings will be as easy as when new.
I agree with @eleeski, it is like skiing warm-cold water, no big issue.