Leave the fuel in floating containers - which have to be delivered by the submerged submarine? Also Western defence strategies rely in submarines being stealthy, but you want to try everyone know roughly where they are?
What problem does this flying boat solve? Does the cost take into account the need for building new submarines to support them?
The Sea Master may have had its uses - but was it as large as a land based maritime patrol aircraft or as manoeuvrable as a fighter or other tactical aircraft?
Seaplanes were the preferred option until experience during the First World War showed the time taken to lower them into the water and launch, and the problems encountered in heavy seas. I believe the Convair Sea Dart was one of a number of experiments conducted by the Americans to deal with the problems on jet aircraft on small carriers.
Angled decks and larger carriers were the answer - or STOVL.
If you look closer into the infighting between the US Air Force and the US Navy of the day it was clear the rejection of flying boats was about keeping face and top brass income, both of which the navy lost.
Larger carriers had already been proposed, the United States having been scrapped a week after constuction began.
The SeaMaster was a pawn, sacrificed to give time for something that could be fitted on a floating hull, based solely on ;
1) being prone to running out of fuel, and
2) submarines were the only vessel able to refuel a stricken SeaMaster.
No other alternatives for refuelling were put forward, since they didn't want the budget for super carrier construction to be under scrutiny a second time.
(Tbh I don't know how thirsty the protoype might have been with ramjet engines, the atomic powered proposal might have been another nail in its coffin, for entirely different reasons).
Yes it was larger than maritime patrol craft of the era, designed to satisfy specific criteria issued by the govenment of the day, beating the Convair alternative which would have been similar in size, (nothing to do with Sea Dart, a sea-based interceptor and not a nuclear weapons delivery system).
Slightly off toipic - there was this little curiosity waiting in the wings that might have banjaxed submarines as well.
en.wikipedia.org
I would propose Polaris just happened to came along at the wrong time for the Air Force and the right time for the Navy.