Sorry to say but if you have a 20 foot boat with a 35 gallon tank you are taking some chances fishing the Mud Hole.
Let's say you get 2 miles per gallon and to be on the safe side 30 of that is useable since most tanks you can't get every drop of fuel out of. That makes your total round trip 60 miles.. Now lets apply the 1/3 in reserve rule to this. The assumption in this rule is you should never count on good running conditions due to weather (a storm, winds etc) and for this reason, to be safe you have to assume that you might not be able to run up on plane which could cause your mileage to be cut in half. Thats means for safetly reasons your safe round trip margin is actually around 40 miles. 20 out and 20 back and no margin for trolling.
If you pick your days you might be OK but is it worth the risk? Not for me but I'm sure others have done it.
As far as the fishing out there, sharks in June and July drifting chum and dead baits. Follow this link and page down to sharks for some tips
http://www.njfishing.com/Fish_Species.php Mahi and an occational school Bluefin August and September trolling.