I've got the 175s. SCsolar recommended Sharp as they have one of the more sturdy
aluminum frames, the monocrystalline 175s are not as effecient as the
current leader, which is Sunpower, for efficiency, but they were the most efficient panels being produced prior to Sunpower. The Sharp 175s are also shade tolerant. And yes, they do have an exclusion for exposure to saltwater. Every
solar panel has a broad disclaimer on "abuse" or inappropriate
installation, so I'm sure if you ended up dunking a panel in the
water most panel manufacturers would void the warranty.