Wednesday, March 07, 2012

Captain John: A Heavy Duty Pump In A Pinch

Captain John explains how to make a small diesel engine dewatering pump to get water out of your sailboat fast...

Guest blog by Captain John
Captain John Jamieson, a regular contributor to the Daily Boater, is author of Seamanship Secrets and publisher of the popular boating education website

It’s been a fine boating day, and you’re nestled in the perfect anchorage. With a mug o’ rum and a fine imported stogie, it just doesn’t get better than this. You stare lazily up at the canopy of twinkling prisms above your head.

Thirty minutes later, you groggily pick yourself up and mender down the companionway. You never make it past the last step…

You slip off the ladder and tumble onto all fours, landing in 6 inches of ice cold, brackish water. It’s pouring in - but from where?

Pump It Out Fast
Use your small diesel engine as an emergency dewatering pump to remove lots of water fast. First, locate the source of the flood water. Look inside the boat diesel engine compartment, under berths and inside bilge areas. Check seacocks and hoses.

Automatic bilge pumps or hand bilge pumps do not have the capacity to handle large volumes of flood water. On a small pocket cruiser, you need to get rid of that water fast to prevent capsize. Make preparations today to keep things simple in future emergencies that happen in heavy weather or at nighttime,.

Pick up four items at any hardware store. Before you leave, measure the outside and inside diameter of your boat diesel’s raw water intake hose.

Boat Diesel Pump Parts Needed
•    one 8-10” length of clear PVC tube (equal to inside diameter of raw water hose)
•    six  stainless steel hose clamps
•    one 6-8 foot length of flexible hose (equal to outside diameter of raw water hose)
•    one 12” square of fine mesh nylon or bronze screen

Small Engine Dewatering Pump Steps

1.     Shut down the small diesel engine.

2.    Shut off boat diesel raw water seacock. Make sure to place the seacock handle at a 90 degree angle to the diesel engine raw water intake hose.

3.    Pull off the raw water hose from top tailpiece of the seacock.

4.    Insert the clear PVC tube 2” into the raw water hose and double clamp. Insert the PVC tube 2” into the flexible hose and double clamp. Double clamp the screen material over the intake end.  (To save time in an actual emergency, complete this step ahead of time).

5.    Stick the screened intake end deep into water. Start the small diesel engine and check to make sure you have exhaust water discharging over the side. Keep an eye on the clear PVC tube for adequate water flow.

6.    Assign one of your sailing crew to check the overboard water exhaust. If you lose suction or exhaust water fails to flow, shut down the engine right away. Watch for debris to clog the intake end of the dewatering pump.

Take the time now to prepare your boat diesel emergency dewatering pump. This will help prepare you and your sailing crew for future flooding emergencies.


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Photo ©© Sebastian Duda


1 comment:

  1. I'm thinking that it might be possible to arrange it as a Y on the intake, so it's even faster to make the switch in an emergency.

    Any thoughts from those who may have tried it?