• 4.25" OTW Dive Module - SINGLE SHAFT

    The front section houses the positive and negative input terminals , reversible water pump, solenoid valve, the pump control unit and forward push rod. The latter three are mounted on a CNC`d tray. This front tube is attached to the middle ballast tank by three brass tiebars.


    The ballast tank has three water probes which control the pump and the fail safes. Baffles to prevent tank sloshing are mounted on the central conduit which allows the power and servo cables to run from front to back.


    The third and final tube, also connected by three tie-bars to the ballast tank, has its own CNC’d tray and supports the propulsion motor(s), speed control unit, and two push-rods for the rudder and rear dive planes.


    All push rods are stainless steel and come with clevises and waterproof bellows.


    All OTW Dive Modules run on 12 volts and have two fail-safes incorporated as standard (low voltage and loss of radio signal). All wiring is connected with Tamiya plugs. Single and dual motor options are available.


    Dive Modules come fully assembled and tested.



    • Details

      The module comes with the following items:

      • Two drive motors complete with motor mounts and waterproof shaft housings for the propeller shafts.
      • A speed controller rated up to 30 amps.
      • A BEC, which allows you to run the whole system AND the radio off a 12V battery.
      • Reversible water pump and hydraulic valve.
      • Electronic pump management system that is complete with two failsafe modes.
      • Three ballast tank probes.
      • Three stainless steel pushrods and clevises.
      • Three waterproof silicone rubber bellows for the control rods.
      • Two waterproof external battery connectors, one positive and one negative.
      • A set of baffles in the ballast tank.


      The electronic components are mounted on two easily removable trays. All internal connectors are of the Tamiya type. 90% of the components are produced in-house.

    • Shipping and Final Price

      These systems are sourced from the UK and due to the fluctuating USD/British Pound, the Nautilus Drydocks reserves the right to adjust final price depending on current exchange rates. 

      Shipping prices will likewise be adjusted at the time of final invoicing.

      For any questions, or for an accurate quote, please contact us and we will return your inquiry immediately.

    Ballast Tank length


    The Nautilus Drydocks is the world's premier supplier of kits, parts, components and resources dedicated to the hobby of remote controlled submarines. 



    983 Tivoli Dr
    Naples, FL  34104 USA
    Phone: (239) 877-4280

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