Coast Guard Dewatering Pump Operations

Dewatering pump. Photo: AMSEA.

By Jerry Dzugan, AMSEA

In a flooding emergency, you can’t expect a rescue resource or good Samaritan to be waiting nearby.

Vessel flooding and its often related instability are the most common source of fishing vessel losses. Consider the distance that a Coast Guard helicopter has to travel to deliver dewatering pumps. Plus, they don’t carry a pump on every routine flight due to weight constraints.

It makes sense and is a good maritime practice to have your own dewatering pumps and bilge alarms.

The quickest way to have a pump available is to have your own dewatering pump installed and maintained. Remember that an ordinary bilge pump is rated by the number of gallons it can pump in an hour. You want a pump that is rated for gallons per minute—a dewatering pump. The pump(s) should be able to pump water from every watertight compartment of the vessel. 

If you do not have a dewatering pump, make sure to contact the Coast Guard early during the emergency to let them know you have a problem or a potential problem.

The Coast Guard would rather respond to an emergency and have it canceled in route because the problem is under control, rather than get to the location and have to conduct a search for people in the water.

If it is determined by the rescue crew to be low risk, they may deploy a rescue swimmer to the vessel to help operate the pump. Rescue swimmers are responsible for pump maintenance and changing fuel out every 90 days and are very skilled.

However, due to the vessel’s condition or weather it may not be an acceptable risk to put another person on the vessel. In that case, the pump, flashlight and short instructions on how to assemble and use the pump will be delivered via a hoist from the helicopter.

Once on scene, the Coast Guard will give you directions on the VHF on how to position your vessel and receive the pump. Stay in regular communication and follow their directions.

The pump they will lower to you from the helicopter is a Honda model GX120, also known as a P1B. These pumps are more familiar to vessel operators and have a rating of 120 gallons per minute depending on the vertical distance of the pump from the water being pumped.

To give a sense of scale, a 2.5 inch hole one foot below the waterline will let in 123 gallons of water/minute. The same sized hole three feet below the waterline will admit 213 gallons/minute, which means you would need at least two P1B pumps. The deeper the hole is underwater, the greater the amount of water that will enter. A dewatering pump delivered from a Coast Guard vessel will have about twice the capacity of the P1B.

Following are some tips on the use of a P1B dewatering pump:

1. Attach the quick connect gas hose to the red fuel tank on top of the pump. Open the fuel tank vent on top.

2. Attach the 15-foot ribbed water pickup hose securely to the engine with the cam cleats.  At the opposite end of the hose is a metal perforated strainer that needs to be kept completely under water. If not, it will suck in air and the pump will stop. Some Coast Guard air stations will secure a lead weight at the end of the tube to keep it underwater,  

3. A blue three-inch diameter discharge hose is already attached to the pump and is 20 feet long. It should be rolled out with no kinks and the discharge end should be tied off to a rail or held by someone. Once the water is discharged from the hose, if not held securely, the hose can be wild and clear the decks of people and gear. The loose end of this hose will have a red plug inside a rubber extension of the hose. Do not cut this plug off or try to remove it! The plug is needed to maintain back pressure. Cutting off the plug will prevent the pump from working. It’s designed so the rubber around the plug will expand so the discharge water can exit under pressure. 

4. On the side of the flywheel cover, opposite the pull start cord, is an ignition on/off switch. Some Coast Guard air stations have removed this switch so it is always in the “on” position. Make sure the switch is in the “on” position.

5. On the pull cord side of the flywheel, are three switches line up vertically.

Turn the bottom black switch to the right to turn on the fuel.
Turn the middle grey switch to the left to turn on the choke.
The top large metal switch is the throttle. Push lever to left to increase speed.

6. Use hand pump to prime the pump. Keep pumping until water comes out the outlet below the handle. 

7. Pull the cord to start. If it doesn’t start on the second pull, turn middle grey choke to right to turn off choke and pull cord again. Giving it too much choke will flood the carburetor and make it difficult to start.

8. The pump comes with two tanks of gasoline, each enough to run for 2.5 hours depending on the speed you run it. If you are quick about it, you can disconnect the first tank when fuel is low and connect the second gas tank and the engine will not miss a beat. The pump also comes with a flashlight and short instructions in four languages. You may want to keep this list of expanded instructions onboard for reference.

Also, beware of using a gas pump in an enclosed space due to carbon monoxide risk and review pump use before an emergency. If you have a pump, start it as part of your monthly drills. Remember, in an emergency, minutes count.

A four-minute video on P1B pump operation is available at www.amsea.org/amseavideos.