The seastead will have 4-foot-wide columns mounted at its corners, extending 13 feet into the water at a 45-degree angle. Cables will connect the bottom of the columns to the adjacent corners for stability. The seastead weighs approximately 30,000 lbs and features a design similar to a small oil platform, emphasizing structural stability and drag reduction. Normal operation will utilize two submersible mixers with 2.5-meter propellers, while a dingy with a Yamaha Harmo 3.7 kW electric motor will serve as a backup propulsion and emergency tug-boat.
While Yamaha supports "twin mode" for two motors, running three Harmo motors in parallel is not officially supported. However, with proper configuration and engineering, it may be feasible. Three motors could provide approximately 700 lbs of thrust, sufficient to move the seastead at 0.5 MPH in no wind conditions. Advanced control systems would be required to synchronize the three motors.
The dingy, equipped with up to three Harmo motors, can function as a tug-boat in emergencies. The motors' high thrust-to-power ratio and remote operation capability make this setup feasible. However, the effectiveness of the tug would depend on factors such as wave height, waterline area, and motor placement on the dingy.
RotoMolded Polyethylene (RPE) boats are durable, versatile, and ideal for utility applications. They are resistant to UV radiation, impact, and abrasion, making them suitable for marine use. Below are some options in the 4 to 5-meter range:
Alumax offers a range of HDPE boats, including utility and fishing boats. Prices start at approximately $3,000 for smaller models.