Oh, what luck.
If you are still in Manila, can you make it out to any of the large markets? Divisoria, perhaps? You can find anything under the sun at Divisoria, it is thee open air market in the country. If all else fails, do what my recommendation is to everyone visiting, go to the supermarket. The supermarkets cater to the wealthy and tourists who want fruits out of season. If Durian is not at the open air market, then the supermarket will have it imported from Thailand or Malaysia, along with mangosteen, lanzones, santol, etc.
No, Durian is not "king" in the Philippines. Davao is generally where this grows, and the locals enjoy it more. The north is not as "tropical" as the south, though far more tropical still than Florida. It just doesn't grow as easily, and therefore isn't as popular.
Filipinos do not like "stinky" fruit, in general. Langka(jackfruit) is usually the upper limit of fruit stink. Marang although not stinky to me(musky maybe), will offend some Filipinos. I was taught the Soursop is ripe when you press the outside, and it gives somewhat to your finger. Then chill it, and start stripping it of its segments.
As for Subic, this is an old time location of American presence, as your fellow sailors have probably told you. You may not be able to find tons of diversity in fruit, but there's lots of good places to buy wooden crafts, and where most of the US military would get their mahogany military plaques made. The carvers are way talented.
It's rainy season ... not typically the most abundant fruit wise, but you should be able to find some goodies. Enjoy.
