It would be interesting to be able to customize the size, width and the depth of your knarrs to suit different purposes:
- a war knarr, fast and able to carry more people onboard. High in cost and is a valuable trophy;
- transporter knarr, with more transporting slots;
- whale/kraken/walrus/whatever hunting knarr protects the passengers from a few hits by the mobs.
The division between the ship types would allow to visually differ the wealth and the power of a faction as well.
Potentially, people should be able to progress to more developed ships with multiple sales and etc.