My idea now is to try and run the engine from a gas can to try and isolate the problem. Which line on the carbs is the feed and which is the return. It seems like the vent is in the fuel cap on my boat is that correct?
I'm not sure if the fuel cap on your boat serves as the vent but not as far as I know. I believe there's a separate vent. As far as I know, Seadoo didn't use venting fuel caps and that's pretty unusual for boats and watercraft in general, based on my experience.
Running the engine from a gas can (using pre-mix fuel where applicable) is a valid test IMO, be careful not to spill fuel into the bilge of course.
The fuel supply is connected to the fuel pump, sometimes the pump will be divorced from the engine on some boats, or on the side of the carburetor on others, depending on the model. Pulsations from the engine crankcase are used to operate the fuel pump diaphragm, so you'll see a tube connected from the crankcase to the pulse port on the fuel pump. Leave this as is, connect the fuel tank/can to the inlet port where the fuel tank normally connects.
There's a fuel return on this setup that normally leads back to the fuel tank, so while running fuel will be pumping out of the return and entering the main tank UNLESS you re-route this to the gas can.
But honestly, given it ran okay for more than 10minutes, seems your fuel tank is experiencing a PARTIAL VACUUM so unscrewing the filler cap should alleviate that for testing purposes.