213kWh feels like quite a lot of juice. Admittedly, I usually don’t go at planing speeds.
I have an 80Ah lead-acid battery to power the electric trolling motor on my inflatable dinghy. That’s 80A*12V = 0.96kWh. That gives me 5-10Nm range depending on speed. My dinghy would sink with 213kWh on board.
My 7 tonne sailboat uses ~2l/h of diesel at twice the speed. 213kWh of lead-acid would double the weight.
Last time they tried to wage arctic warfare they lost more men to the cold than bullets and artillery.