I like to use wood candle sticks as pedastals mounted on a stained wood base. I simply drill holes in the bottom of the hull after filling the lower half of the hull with resin to serve as a solid medium in which to hold the mounting posts on the candle sticks. I paint the pedastals brass or gold and place the mounted submarine in a display case. The candle sticks and the base board are available in any craft store or Walmart.
For 1/700 scale boats, I have used light blue cloth to cover a stepped base. After covering the stepped base in a pleasing display, I mounted Soviet submarines on different levels and placed all in a case. Thus, I have my cold war display for both Soviet and USN submarines. It proved an interesting approach.
Bill Morrison