I've seen a couple of seals in the Merrimac myself when fishing the northern end of Plum Island, and was equally enthralled, even though they were very far away.
Yesterday, fishing at the mouth of the Mousam River in Maine, a big-ass seal scared the living daylights out of me when he suddenly surfaced just out of casting range. I was way out on a sandbar, tide ripping out, in a little too deep, with rollers crashing on me occasionally. Already a little unnerved, let's just say I got a little weak in the knees when he popped up to check me out. His head was the size of my computer monitor! (now there's a real wildlife metaphor for ya) <G> After I regained my nerves, we had a couple moments of mutal admiration (after all, I was using the new 8-wt), we both smiled and then he was off, no doubt fishing much better than I.