Meant to say - probably the best viewpoint for L Coruisk is from a very rocky hill, called Sgurr na Stri, at the seaward end of the loch, but is not a climb for a casual walker.
Also the boat will land you at the jetty in sea Loch Scavaig and you'd need to get over the Scavaig river by boulder hopping (impossible when in spate) to get to Sgurr na Stri.
I'd walk from the jetty round to L Coruisk and try to get a little elevation on that shore. Should be able to find a spot after walking for about 20 mins.
Plenty seals in L Scavaig and the water is crystal clear.