Plum Island was good a couple of days ago for me about an hour before low tide
right at the point before the sandbar. At low, all action ceased, although acc.
to other reports it picked up again a little bit once the tide started to turn
around. If you go there, I suggest you get there early before the chaise lounge
crowd sets up shop.
Rarely have a chance to get to Maine, so can't comment on that one.
-bd