If you’re headed to Whiteswan Lake this summer, keep an eye out for an unusual vessel cruising mainly below the surface of the water.

Windermere resident Hank Pronk has crafted an 18-foot submarine, and plans to cruise it around the lake this summer.

Pronk took the sub for its maiden voyage last Tuesday at Windermere Beach — where a paddle wheeler he built is also currently moored — but says he plans to move the craft to the other lake for the summer.

The submarine, built using a repurposed propane tank, is actually Pronk’s third. He built his first sub at the age of 16, though he says he has no idea where the idea for the hobby originally came from.

“This third one, it’s a different design,” he says. “This one is intended to be able to travel around with a diesel engine, so it’s a little different. It’s like the old World War Two subs.”

While handling the sub is still tricky, Pronk says the initial voyage went smoothly and he’s expecting to improve with practice.