The question isn't "Why would you build a hot tub boat with a gas-fired fireplace"; the question is, why wouldn't you? The Spacruzzi Hot Tub Boat is exactly what the name implies: A fiberglass, teardrop-shaped combination hot tub and boat hull with a fireplace. The vessel is powered by a battery and electric motor, with a four to five-hour cruise time at a leisurely pace. The batteries are also swappable, so one can be kept charged in reserve. An onboard UV and saltwater filtration system keeps water fresh while dockside, and an onboard heater and circulation system works while underway. All components are removable and serviceable. The Spacruzzi is made in the USA and available for order now.