I am not sure but i think you'd have to travel to Maine/New Hampshire for a seal dive. Keep me posted as this progresses, I'll try to get at least 1 dive with the group
Cape Ann Dives offers Seal Dives throughout the Year, usually on Friday's. Just call the store or check their website to see when / if one is scheduled. That's the most cost effective way of doing a Seal dive trip with them. If you want to schedule one yourself, with them, then you'll run into what I ran into last year. See the Happy Hour thread from last year.