5
OPERATING YOUR SEA EAGLE
Motor Selection
The STS-10 can take an electric trolling motor or small gas motor up to 4 hp. Because of its light weight, the STS-10
only needs a small trolling motor such as the Watersnake Venom 34 or Minn Kota Endura 30. For gas motors, a 20”
shaft (“long shaft”) is recommended.
Gas Powered
Some of the advantages of gas motors over electric trolling motors include; increased range over battery powered
motors, ample power against a headwind, and they do not require a heavy marine deep cell battery or expensive
lithium ion batteries. Disadvantages include; high initial cost, maintenance costs and gasoline storage. A 20” long shaft
works best. A 15” short-shaft motor will work only at low speed and the boat must be weighted towards the rear, oth-
erwise the propeller will pull air down from the surface.
The STS-10 is a “displacement hull” that does not plane, it pushes up a wave at the bow and cannot overcome the
wave. A gas motor can provide more power than the STS-10 can take advantage of. In calm conditions, the speed of
the boat is limited to its hull speed of approximately 4 mph. Beyond a certain setting, approximately ¼ throttle, the
motor may shake, ventilate (pull air down to the propeller), or the sound may change to a deep rumbling with no
increase in speed (lugging). For these reasons, using more than a small motor like a Honda 2.3 hp is not needed.
Torqeedo and similar electric motors are powerful like gas motors and perform like gas motors..
Electric Trolling Motor
Some advantages of trolling motors are; their low cost, light weight, ease of storage, low maintenance requirements,
quiet operation, and usability in bodies of water that prohibit gas motors.
There are some basic features to know in order to understand electric motors. The thrust rating of a motor is also its
maximum electrical draw in amps. A 30 lb thrust motor draws about 30 amps on the highest setting. To extend range,
operate the motor on a lower setting. For example, the Watersnake Venom 34 has five settings, and draws
approximately 12 amps on the #3 power setting. Watersnake and Minn Kota trolling motors can easily push the STS-10
to its hull speed. According to Minn Kota, their trolling motor propellers are pitched to push a boat at approximately 4
mph. A larger thrust motor will not appreciably raise the speed of the boat, but could help in a strong headwind.
In a river or tidal current, the STS-10 cannot make progress against a current that is more than its hull speed or the
speed of the trolling motor. Forward speed will vary depending on conditions, but if the current is moving faster than
the boat can go, it cannot make headway and may go backwards relative to land. Because of the limits of a
displacement hull, adding a larger motor may not be effective.
