Speedboat One of a series of radio control fiberglass motor boats, I was surprised to find that hull designs which discouraged laminar flow had significantly higher top speed, although wallowing at lower speeds.	Twin 17t 7.2v Access was to drivetrain was provided removing a hatch cover, sealed from the intrusion of water by the compression of a compliant latex tube. To dissipate potentially destructive heat from the motors and speed control, I ran a small coolant pump with dynamic pickup.	Counter-rotation Finding that surface piercing props would create a sideways thrust requiring performance reducing course corrections, I introduced counter-rotation in this version. Another challenge of sealing mechanical penetrations was overcome by sourcing very finely made telescoping brass tubes and rods.