sea level is sea level in the container, changing the size z in the container!?

how to make that sea level was equal to the sea level in the container (that had not been performed), if I change the container grid(z size)?

You can change the ocean level in the Rendering rollout of the Simulator. The Ocean level should represent roughly the value for the initial fill up.

I put in dynamics(inertial fill up) -42, and ocean level 42
container of water appears above..

Unfortunately you need to play a bit with these values and see what value works best. Try with a little bit more and a little bit less and check which one works for you.

what value should be approximately in the initial fill up(dynamics), if the value of ocean level(rendering)- 50 ?

in the process I want to show as the ship leaves a trail on the water

value of 49 would be good to display marks on the water?

You just have to try and find the best one for your scene. You can check our sample ship scene. There the initial fill up value is set to 42 and the ocean level is set to 41.5.