Note: here I will be referring to terracotta, this includes reinforced wood for crafts that support it.

My idea is that the least (percentage of the max terracotta it can have) armor blocks a craft has, the faster it goes.

This would be limited to only crafts with armor, and only terracotta, glazed terracotta wouldn't count.

The boost would be balanced by the fact that the craft has considerably less HP.

The boost would start from 0% (all possible terracotta used) to a max% (0 terracotta used) , depending from the craft type.

For example, a destroyer can have a max of 25% terracotta. Let's give it a max speed boost, let's say 20% (this is an example) . If, building the ship, you only put 13.5% of the blocks as terracotta, you used 90% of the possible armor blocks. You'd then get 10% of the speed boost, in this case 2%

For example, a destroyer has 25