Goto Reviews reports on SeaOtter Woodworks, a company based in Alaska that builds hot tubs by hand with Western Red Cedar. They support sound forest management practices — much of the cedar is salvaged windfall and sustainably harvested by small family mills in the towns of Southeast Alaska.
The tubs can be heated by electricity, propane or wood heat. The wood heater is a "Chofu Fired Wood Heater" which is popular in Japan. This heater uses no electricity, has no pump and drives no jets. It heats water quietly by natural convection or "thermosiphon". The heater is constructed with a stainless steel water jacket surrounding an airtight firebox.