Hi I'm new to this forum and do not know if I'm at the right place, here goes... I purchase a premium ship and can not use my ship XP. All the answers are convert you ship XP and gold to upgrade, I do not want to use all my gold. My suggestion is to convert my useless premium ship's XP into gold, for instance: 1 gold = 1000 ship XP or 10 gold = 1000 or what ever is good for the developers. Both sides wins. A new ship could be brought and I get gold to upgrade.
On standard ships all you have to do is upgrade to another ship is use you ship's XP without you using your gold if you have enough XP on present ship.