I don't think the 796 can do this. I'm pretty sure the 396/996 can, because the service searches are basically set up as systems in the scanner, so it's treated like a system but is scanned like a search.
There are not that many channels used in the marine band, you could easily program them into part of a bank. Since you're in Canada, make sure you use a list that includes the Bravo freqs as well as the Alpha freqs