I cant see around the cylinder head
joint in yr pic but yr top cover with thermostat & anode in it that has the salt
around it is definitely leaking. Easy to fix with silicone. These engines need flushing
occaissionally with acid type desalting solution, there are you tube vids on how to do that.
There should be be no salting around any joints on the engine
as it shows a leak.
I recommend using threadlocker such as loctite 242 or equiv on every bolt on yr engine as they vibrate a lot.
If the engine starts quickly & doesnt blow black smoke except on sudden throttle increase its unlikely the head gasket
Yr engine looks good for a salt water
one of that era.
Gotta watch the exhaust
elbows too, the design is bad in that when it fails it can drop salt water
on top of exhaust
valve & if its open......