What to bring on a long ride?

50 miles?  2 bottles gatorade (or if you're sick of it, accelerade), 1 bottle water, 2-3 gels, something you can eat (fruit, pb&j, clif bars, whatever sits), endurolytes. That's it.

70 miles?  Add another gatorade(or accelerade), gel, and some more endurolytes.

This is assuming a pretty 'normal' sweat rate and no really rediculous nutrition needs.  Doesn't need to be complicated.

Depends on what's in the bottles.....  I use either Infinit or Carbo Pro + Gatorade Endurance on long training rides (50+), plus maybe 1 or 2 gels.  I don't need any food on these rides (may throw a Clif bar in there for variety).  Figure out how long it will take you, you'll likely need 250 or so calories an hour (guesstimate here).  Figure out how many calories are in your bottles (I don't think I could stand gatorade for three hours....), and take enough bottles accordingly.  You can also take powder and mix up something new along the way.

Since time is short, maybe try the Perpetuem (some people like it).  If you don't like it, you'll find out soon enough

Your in FL should be bloody hot. For me my goal would to drink 1.5-2 water bottles of some type of sports drink you are used to an hour. For me that simple Gatorade Endurance or regular Gatorade with extra electrolytes via endurolyte powder.

I try and drink 150 calories of sports drink and then also drink water. Plus eat 100 calories and hour for a total of about 250/hour. We are about the same size so I would think it would be close for you too.

I would then try and eat about 100 calories an hour additional. I set my watch to beep every 20' and eat 33 calories either one shot blok, fig newton, 6 sugar babies, or something like that...if you eat regular candy go for gummy worms or something like that w/o fat.

You could do gels if you are used to them and just do one per hour. 

For me to do 70 miles I'd either loop back to my car and have a cooler there with more bottles of fluid or plan on stopping and buying/filling up at a store.

I'm doing a triple loop of 25 miles Saturday and I'll bring 4 extra bottles to swap out and more water refill my aerobottle. If you stop at your car you could eat something then too. 

Fifty miles is a long ride?

Seriously, I've been riding a 56-mile loop pretty regular lately, get by with my (70-oz) camelback and a waterbottle filled with Gatorade, a back-up bottle of water, and a Clif Bar halfway through. For a 70-miler I would stop at a store or loop back by the house to replenish the Gatorade, and maybe have another Clif Bar.

For my 3-hour rides I have been bringing the following nutrition:

1 bottle gatorade
1 bottle water
2 packages of clif shot bloks (400 cal total) - of which I usuall eat about 1.5 packs

I do these rides in the morning when the temp is ~65-70F and humidity <50%, so extreme fluid loss is not really an issue.

When I extend to 4 hours I will probably loop back by the house to refill the bottles and maybe add in a clif bar to get some solid food.

Carry with you:
Cell Phone
CO2, flat kit
extra tube

Nutrition:
Treat it like you would a Tri.  What are you going to do then nutrition-wise.  I take in 400 Kcal/hr so I do the same for all my rides.  That's 2 gels and a hammer bar/ hr.  I take Nuun, so I have a tube with me for when I get more water. 

So if you're going 70 miles and it's a double out and back and I know your FAST it'll take you 1hr 45 min/loop.  So all you need is two bottles of water, 4 gels and 2 bars.  Get back to your car reload and go.

Pith helmet, bird identification book, jeweler's eye, .410 guage for 'critters', yo-yo for when you're riding with no hands and want to 'walk-the-dog' & a moist towlette.

And what the others said

Here's how it went...

We swam a mile first.  The water was awesome and fishies were swimming under us.  Cool. 

Then we changed and hit the road at about 830am?? .  Of course I get dropped.  That's what happens when I try to haul my fat over a steep bridge, when I reached the apex everyone was long gone.  Then I got lost (went south instead of north- the road is confusing if you've never been to St Armands circle and don't know wtf to go). Eventually found my way after a few extra miles.  I knew I was on the right track when I saw Wendi!

In the Polar bottle- three hr bottle of Perpeteum.  Okay, let's just say that stuff grows on you.   I drank about 2/3rds of it. Two water bottles and a flask of gel (took two oz).  Guy convinced me to try Endurolytes, so I had two, one at start and one 90 minutes later. In hindsight, maybe I could've used a couple more (3 hr ride).  

Ran out of water at mile 30 and me and another guy went to the gas station to get more.  It was freakin' hot at 11am!!  I also put more (cold!) water in the Perpeteum bottle trying to dilute it to taste better but I only took a couple swigs after that.

Got back to the cars at mile 37 (since I was lost and didn't know WTF I was I turned back earlier than I was supposed to- they caught me later on).   Got to car, refuel.  I was fine since we just got more water.  Went back out for 16 more miles, it's all I could stand.  

showered at the beach and changed, went to eat.  I felt really nauseated, don't know if it was the heat, exertion (multiple trips over multiple bridges) or the perpeteum.  

and thanks to the person who suggested CASH... I put that in the bag at the last minute.  Needed it! 

Thanks, ya'll.