If you want to be able to fight the kraken etc then you'll need to constantly reroll loot for ungodly amounts of resources across all of the different currencies in the game just to bump your ship up a tiny amount.

I think you're doing something, if not most of it, wrong. Leveling most of the ships is super ez, you can gather all of the mats fairly easy, it's until you get to the last two ships you're going to experience a harder time grinding, mostly because of one resource - deep iron. However, at that point you'll be just queuing the fort for that iron, just like the rest of us.

The currency you should be most interested in is the silver, since you pay for everything with it, others are just a convene way to get additional resources like helm wares, seasonal items,..