Sailing with Epheria cog and exploring the sea is so much fun and it's a very good way for people who dont care about bartering and sea monster hunting to explore sea grinding areas with a fast boat. But, it has a very very short lifespan of around 30 minutes of sailing which completely ruins the experience. The crafting procecss is also fairly hard because you need to gather 2500 logs to make 25 standardized square timbers which is around 2 or 3 hours of gathering and after that you need to craft it for about 3 or 4 hours more at a shipyard.
My suggestion is that you can increase the crafting cost from around 10mil silver to maybe 100mil silver and make it a permanenet repairable boat. The best way for this is to increase the crafting permit cost not materials amount especially the square timbers because they take alot of time to gather.
I hope this reaches the devs.