You don't need a torque converter to use a car auto tranny in a boat. The wet clutches are super similar to the ones in Velvet Drive. With some clever finagling you can render the torque converter into the mechanical equivalent of a brick, then modify the valve body to select the gear you want.
Harker's island boys have been running car engines and trannies in boats for as long as cars have had engines and trannies.
Auto trans, std trans, whatever they can find.
You do need a thrust bearing, though.
Dave- you drive a CVT? I think you need to turn in your Gearhead card!!!
Now, that's what I'm talken bout!!