I like both, but if i had to choose one it would probably be boat diving (if it is for a drift dive), otherwise, if i'm going to need to surface swim to a boat, it isn't much different from shore diving. Though, I guess i really only like shore diving because the only time I do it is to look for fossils, and I like fossil hunting, so, i might be biased. (Yes i can also fossil hunt from the boat, but sometimes, only sometimes, i can get sea sick, so shore diving certainly prevents that).