RE: Mackie sushi, did you take the membrane off or did you skin the fillet?
If you eat it with the membrane it's very chewy, but if you take the skin off, it doesn't taste as nice with the skin on. Not sure how practical it is to take the membrane off on a bobbing boat but when you are at home try peeling the thin plasticky membrane off, it's a bit extra work but personally I think it's well worth it.