Need Engine Help

First what I have - 2006 Supra 21V which I love. Now the problem that I can't figure out. I am also not a mechanic at heart so I am learning as I go.
Problem - So, over the course of a month and a half we would wakeboard real hard for about an hour and then roll up to eat lunch. Come back out and the engine fires and chokes out like its not getting fuel. Try to restart and just sounds like it wants to fire up but wont. So we wait 30 minutes. Try again and it fires up. We drive off and head home. So I take it to be serviced and they said I had a shorted fuse. Not sure which one (my bad). So try again next weekend. Same thing happens. I call marina, they ask me what size battery I am using. He thinks batter is too small(cca's) so I buy an optima blue top (yeah $200 battery). Take it out again and we run hard and stop to eat lunch. Go to fire up and boat chokes out again. So, we get back and I change the fuel filter. We go out this past weekend. I go to turn the key, there is a pause(like no juice is reaching engine) then voom it fires up. We run hard and we take a break. I go to fire back up and I get nothing. Like no juice what so ever. So, I turn key back to off wait a few seconds then turn the key back on and there is pause no juice then voom it fires back up. We board some more and then head home. Totally weird and the boat performs just fine while running. No hesitations or anything????

Sorry for the long thread but I want you guys to know how it is acting exactly. So any advise is greatly appreciated and I am not sure what it could be but would rather try to fix it my self than pay the Marina and get charged up the you know what.

Thanks.

Vapor lock. Your dealer should be aware of this problem. Avoid running gas with ethanol in it. Use the blue stabil ethanol treatment in your gas. If you are going to stop and sit for a while after running your engine hard, prop the engine hatch up to let the engine cool off.

Indmar also has a 2nd fuel pump kit that can be intalled to help.

Not firing up after you've been running hard is usually caused by heat in the engine compartment. Two things can happen. One is vapor lock in the fuel line, rail, or carb. The second is heat soak in the starter or solenoid that shows a problem not seen on cold start.
Jon has the first one nailed. If that doesn't fix it your problems are bigger.
Not cranking because of heat soak is fixed by replacing the defective parts but opening the hatch will stop the heat soak and fix that for a while also.
Run for a bit with a light load to help cool the engine before you shut down and prop the hatch up. Also, take time to check the intake air passage into the engine compartment and the exit vents. They can be blocked by something and stop the engine from getting the cool air it needs.

Thanks for input Jon but I had vapor lock issues back in 2007 and the dealer did say they corrected the issue when I took it in to be serviced. I don't think vapor lock would cause the boat to not even make a noise when I turn the key though??? Keep the suggestions coming.

Art, I do like the idea of heat soak. It does get hot down here in the south. But even on cold starts I am starting to see a pause before it is firing up though. I will certainly check the air intakes to make sure they are clear.

Check the connection on that new battery too. Loosen the terminals then retighten them, and check that the ground to the block is good.

It gets cold up here but I've had heat soak problems like what you describe. The airflow was the problem and the fault that showed up was in the starter windings on mine. With enough heat it would not crank. Fixing the airflow solved it but at some point the starter will have to be replaced on my old boat.

Thanks Art. I hope its just the airflow. I am sure a starter is plenty expensive. And I will check all my connections again. This will be a dumb question to you but where is the ground on the block located (generally). Thanks.

Not sure on your engine. Look for a heavy black cable that probably is bolted low on the block and then runs forward towards the battery.

Cool. thanks for all your help.