The entire Pacific fleet except for the two carriers and the seaplane tender.
As for Collect-A-Navy... I might be mad, but there is a method to my madness. I dont see ships just for their military value, they are also assets and a form of currency. You can't store leftover tonnage, but it is perfectly fine to store a bunch of old ships untill such time as you need them.
As an example I bough BB Poseidon from Atlantis, used it for a bit then traded it back for tonnage and a bunch of destroyers, then I proceeded to sell off the destroyers, actually turning a tidy profit from the whole deal.