RobAck replied:

Depends on what you think a clutch on a winch does. Most electric and hydraulic winches have a clutch that is engaged to wind the winch in or out. Depending on design it also acts as a holding brake to steady the cable when under load but not under power.

Electric winches definately do not operate under water and hydraulic ones suffer a similiar risk as none have fully waterproofed seals to protect the internal workings of the winch itself.

About the only winch that ever did is one that operates from a power take off (PTO) and there are very few of them around these days

RobA

Crackles replied:

Almost all winches have a free wheeling type dog clutch that disconnects the gears, the one exception being a Capstan winch.
Yes they will all work under water. Even the ones with poor seals will work for long periods submerged. Many falsely believe electric winches will short or burn out when underwater but it's certainly not the case. What does happen is the electric motors with cheaper seals will corrode & the gearboxs sieze up. PTO & Hydraulic winches obviously don't have the electrics to worry about but the gears can still suffer from water ingress over time.
Cheers Craig............

Member - Captain (WA) replied:

Can vouch for the fact winches will work under water - saved my 80 series once when stuck. And up till then I didn't believed it would work either. But make sure you do some serious maintenance after such a workout.

Cheers

Captain