Cat Sandwitch. . . J/K  back on topic.  The Leopard 4082 says it has a PEAK wattage over 3500 watts, at 3500 watts and 22.2V that is 158 Amps.

That number will go up if you drop the voltage, but only if you are demanding that power from the motor. (by propping up)

So asuming you set up your boat and choose the best prop running on 6s, you should go with an ESC over 160A.  If it where me, I would go with a 180A ESC.  That should give you lots of head room.

The constant rated power output from that motor on 6s would be closer to 90amps, but can peak up to 158amps "or more" as they state.

With that motor on a 180a ESC and 6s you will have a cool running super efficient boat.