Fishing for Tuna in Boothbay Harbor, Maine ?

Hi,
I live in VT so most of my fishing is freshwater. I am going to trailer my boat to Boothbay Harbor Maine over labor day and am going to go fishing. I have gone there and got stipers in the bay and nearby rivers, but never really gone out fishing deep there. Anyone have any suggestions on trolling for Tuna ? Mackeral seem to be easy to catch up there, can these be trolled as bait and if so, how do I rig them up ? I am guessing that if I am trolling for Tuna, Blues would also be a possibility if they are around, anything else that might hit trolled mackeral ? I have a 23' Wellcraft Eclipse that I have rigged for fishing over the years. Not looking to catch a 400# tuna, but some smaller 30-50# ones would be fun ! Thanks for any help,

Erik

P.S. Same questions concerning the area off of Rye Beach, NH & Isle Shoals.