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Adding a Raw Water Washdown System

If you regularly go cruising or overnighting, you'll find that dirt, clay (I'm from Georgia), and scum lines accumulate in various locations on the boat.

Event though a bucket of water thrown at the crud will work, it's a lot easier having raw water washdown system with a conventional hose and nozzle attached to it. It makes the rinse, wash, rinse process a WHOLE lot easier. Plus you can give that boat a bath away from the dock.

Though it is great for fresh water boating, using salt water to rinse down the swim platform or grill goo from the hull is still a big plus.

Installation steps


First thing to do is to buy the parts. I'd recommend the following:

  • Washdown kit which includes the pump, silt strainer, hose and nozzle (Shurflo make a good kit).

  • Barb T fitting to tie into an existing through hull water inlet line (like generator or engine inlet line). If you can get the boat out of the water and don't want to T into an existing inlet, pickup a through hull fitting and sea-cock valve.

  • Electrical stuff - Wire (see 'General Info' on wire sizing), waterproof toggle switch, fuse holder.

  • Minimum 1/2"  ID braided tubing (to prevent collapse under vacuum).

  • Deck fitting with barb on the inside and standard hose thread on the outside.

  • Optional but highly recommended small accumulator tank (keeps constant pressure at the nozzle).

  • Hose barbs as needed.

  1. Find a good location for the deck fitting. Most people mount it on the stern adjacent to the swim platform. It should have at least 1' of clearance on the front and back sides.

  2. Drill an appropriate sized hole for the deck fitting but don't mount it yet.

  3. Drill a small hole close to the deck fitting hole for the power switch.

  4. If you want to use a dedicated through hull, drill a hole through the bottom of the hull and use 5200 to install the fitting into the hole. Then attach the sea-cock valve to the fitting using Teflon tape. and TURN IT OFF!

  5. If you are using a T to get water from an existing water inlet, turn off the sea-cock valve for that inlet, cut the hose and install the T fitting

  6. Connect the following to each other using a hose or directly using fittings: strainer to inlet side of pump, and accumulator tank (if used) on outlet side of pump.

  7. Now mount the strainer, pump (and optionally accumulator tank) to the boat above the water line (no syphoning wanted...)

  8. Using hose clamps, connect a hose between the water inlet (dedicated sea-cock valve or T fitting) and the silt strainer.

  9. Finally, using hose clamps, connect a hose between the outlet of the pump (or accumulator) to the deck fitting.

  10. Mount the deck fitting to the hull.

  11. Run wiring of the appropriate gauge (see FAQ) between a power source and the pump leaving the positive side disconnected from the pump. If not tying into an existing breaker or fuse, install an inline fuse holder a maximum of 1 foot from the power source.

  12. Connect the switch to the pump by running one wire from one side of the switch to the unconnected positive sire from the power supply and another wire from the other side of the switch to the positive connection on the pump

  13. Now the fun parts.

  14. Open the sea-cock valve for the water supply and check for leaks.

  15. With no hose or nozzle connected, turn on the switch and verify that their are no leaks and that water freely flows from the deck fitting.

  16. Turn off the switch and connect a hose and nozzle

  17. Turn on the switch and verify that the pump eventually stops running (done pressurizing) and again check for leaks.

  18. Turn on the nozzle and enjoy!

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