I have taken my 20' Seafari to the "Florida Middle Grounds" reefs, 70-115 miles offshore from Tampa northward to off Crystal River,
- I ALWAYS file a Float Plan.
- usually leaving from Hernando Beach, which is the closest spot to the Middle Grounds (70 miles).
- I have a 30 gallon tank, and I carry an extra 24 gallons of gas.
- I carry a life raft, and we all wear SOSpenders life preservers.
- I have SSB radio capabilities.
- I carry food and water for 4 people for 7 days, even though there are usually just 2 of us.
- Once there, I generally anchor, and bottom fish, and don't do any trolling, and don't move more than a couple of times.
- I run off the portable tanks first, then the main tank, moving the portables to the front deck to clear the way for fishing.
- I only go out there when the weather is perfect, and the forecast is for it to stay perfect.
- I cruise at about 3800-4000 rpms where I get about 3.8 to 4.1 mpg, and average about 3.9 mpg.
- I generally have 4-6 gallons of fuel left when I return.
- Oh, I never go alone, but always in the company of one or more other boats which have much longer legs than mine, (usually a 21 Rabco with 150 gallon and a 25' Grady with 140 gallon capacity).
- I have a 15hp kicker motor which can bring me home at 7-8 mph if the big motor quits
If you make long trips, ask yourself, "What's the worst thing that can happen?", and then plan for it. DO that several times, and you'll have a semblance of an emergency action plan.
Common Sense is the key. If you don't have it, ask your wife
__________________
Common Sense is learning from your mistakes. Wisdom is learning from the other guy's mistakes.
Fr. Frank says:
Jesus liked fishing, too. He even walked on water to get to the boat!
Currently without a SeaCraft 
(2) Pompano 12' fishing kayaks
'73 Cobia 18' prototype "Casting Skiff", 70hp Mercury