Water Mount Issues

I am trying to make a water mount (boat/ship). If I set the mythicmob to a base water mob (cod) it jumps out of the water instead of floating.

If I set it to a land mob (pig, cow, horse) the floating works fine (thanks to the last update) but I cant set the swim speed. I tried different values in the mob options as well as the mechanic triggered by a skill. If the mob is on land the speed value seems to work, in water it always swims at the same speed.