Wind and wave energy is a long way off being efficient and you can't export it,
Of course energy can be exported.
potentially you could become self sustaining in terms of energy but it's unlikely and currently unknown.
Hmm...
Fresh water (maybe with the exception of the bottled kind is economically unviable).
That's not true. England will have a severe water shortage in the near future, and there are already plans for taking water from Scotland to England, along the 300m contour line IIRC.
Fishing, yeah but when was the last time you were in a supermarket where you noticed a label "fished in Scotland" other than salmon which is mostly fished in farms now and not exclusive to Scotland.
Plenty of times, but then I have ties to the fishing industry and live in a port city.
In fact the environmental lobby is actively resisting any expansion.
Quite rightly too: there has been severe over-fishing.
Shipbuilding, please, get grip the only way that will return is if,through desperation, you'll try to compete with likes of South Korea. Good luck with that.
As the Far East prospers their wages will rise and so the cost of building ships over there will increase.