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Water inevitably intrudes into any boat. MasterCraft boats are designed to expel the water via the bilge system. When on the water, bilge pumps will expel water. Bilge pump sensors allow the system to pump water overboard either automatically or manually. Because the bilge is located in the lowest portion of the boats hull, it is not always readily apparent to individuals on-board whether there is water in the bilge or not. To allow operators the opportunity to manually verify water levels in the bilge, a center access plate or access door is built into every boat. 

All boats (except ProStar) have two drain plugs, which allow water to be drained from the boat when the boat is OUT of the water. There is a center T-handle drain (the only one for a ProStar) and a transom drain plug. When out of the water, on a trailer or lift, water can normally be drained into the bilge system by opening the center drain. 

Boats have sea strainers installed to assist in keeping debris out of the engine and water intake systems such as the ballast system. 


The bilge lines and pumps are beneath the decks. The center drain location will vary slightly by model, but generally is found close to or adjacent to the drivers seat. It will be accessed through a hatch or access plate, which may be under marine carpet. A transom drain plug is on the centerline of the transom. Sea strainers are located in front of the engine. Scuppers, where equipped, are located on the lowest point of the deck, under the rear seats. Bilge pump-out locations are on the side of the boat. Depending on the model, the pump-out may be on the bow or the gunnel. See Guide to Individual Models in the 2017 Owners Manual to determine the location of bilge pump-out. (They are often adjacent to ballast over ow/vents.) Pump-outs should never be obstructed. 

The bilge system is controlled by a switch on the dash panel. The bilge pumps on all V-drive models will be in the automatic mode when the ignition key is turned ON. Some models may have two (2) switches, one for the forward bilge and one for the aft. In these instances, the switches will be marked. The manual and automatic bilge discharge system is never completely OFF. When in the automatic (default) position, a sensor alerts the system to discharge water from the bilge area. 

Boat operators are advised to leave the switch in the automatic position, unless there appears to be excess water in the bilge as viewed through the center plate. In that event, the bilge pump can be manually activated by turning the bilge pump switch to the manual ON position. Return the switch to the automatic position when finished emptying the bilge. Leaving the switch in manual mode can result in damage to the pump and may not be covered by warranty! 

Caution: Return the bilge switch to automatic any time it has been turned to manual to remove water from the bilge. Operators should monitor the water level through the center drain and ensure that the bilge pump(s) does not continue to operate after the bilge is emptied. Note that a small amount of water in the bilge is acceptable, except when winterizing the bilge system. Failure to follow instructions may result in damage to the bilge system, which may not be covered under warranty! 

Drain plugs should be loosened and removed when the boat is out of the water to allow additional drainage of the bilge system. Always ensure that the transom drain plugs have been tightened in place prior to launching the boat into the water. Failure to do so can result in water intruding and overwhelming the system, sinking the boat. 

Warning: Transom plugs should be opened only when the boat is ashore. Removing the plugs allows additional drainage of the bilge system. The transom plugs must always be secured tightly in place prior to launching the boat into the water. Failure to do so will allow water to intrude into the bilge system and may result in serious injury or death as a result of the boat sinking. 

Center drain pie-hole lids should be secured prior to boat operation. It can be possible to misdirect the cross-threads when reinstalling. Retry until the lid is secure, level with the deck. Not only can additional water from the deck intrude if the lid is not secured, but individuals on-board may injure themselves if they misstep in the area of the center drain. 

The sea strainer should be checked before each outing. See the Care and Maintenance section of the 2017 Owners Manual for details on how to properly inspect it. As equipped, the strainer operates automatically and does not require a switch or gauge to monitor. Regular maintenance, however, is important. 

SPECIAL NOTE: Because the bilge pump operates even when the boat is shut OFF to prevent excessive water on board, if the pump runs fairly frequently, it can cause the battery(ies) to fully discharge. This is a signal that the boat is either taking on too much water from a leak or that the boat is being left in the water for periods that are too long. Anytime the battery is low or discharged, properly recharge it prior to operation. 

Bilge pumps will not operate in either the manual or automatic mode if the batteries are fully discharged. This condition may allow excessive water in the hull, which can damage or sink the boat. Make frequent checks of the battery charge and bilge pump function when the boats are moored and exposed to the elements. 


The bilge system is among the most important systems in the boat. Attention should always be paid to proper operation. 

  • If the boat does not automatically pump water out of the system when the ignition key is ON, verify that the bilge switch is turned to automatic. 

  • If it is turned to automatic but still is not pumping when there is evidence of water in the bilge as viewed through the center drain, turn the switch to manual as needed to pump out the water. Be certain to follow the instructions above and do not leave the switch turned to manual after water is evacuated. 

  • If the bilge pump(s) still does not work when turned to manual, check the circuit breaker panel to ensure that electricity is mov- ing between the switch and the pump. If the circuit breaker, which is marked, has tripped, reset it to ON. 

  • If the bilge pump(s) still does not work, it may be evidence of debris in the system or failure of the ballast pump impeller, which must be replaced on a regular basis as detailed in the Care and Maintenance section of this Owners Manual. This is a serious concern. The bilge system keeps the boat from filling with excess water that may cause imbalance in the boats trim. Under the worst possible conditions, the boat can sink. If the system fails while on a body of water, return to shore IMMEDIATELY! Have all people on-board put on PFDs (personal flotation devices). Signal for emergency help. If persons on-board have working cell phones, contact help. After returning to shore, take the boat to an authorized MasterCraft Dealer as soon as possible for repairs and do not use the boat again until it has been properly repaired. 

DANGER: An inoperable bilge system can result in the boat taking on excessive amounts of water, resulting in significant damage to the boat, even sinking. Persons on board should wear PFDs and be prepared to abandon ship if the boat is on an outing. Operators should signal for emergency help and return to shore IMMEDIATELY and have the boat repaired. Failure to follow instructions can result in serious injury or death.

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