Long Island Marine Surveyor

Telephone 631 589-6154  Fax 631 589 0084

 NFPA USSA  FMANA SNAME USNI ABYC 

Long Island Marine Surveyor 631-589-6154

Long Island Marine Surveyor

Boat Bilges

Boat bilges should be clean and orderly.  They should be oil free.    Hoses attached to through hull fitting should be double clamped with a sea cock attached.  Through hull fittings below the waterline must be bronze or brass, plastic fitting can crack.  Wiring must be neatly tied not loose wiring should be hanging about.  Bilge pumps should be working.  One or more automatic DC/electric submersible bilge pumps with automatic and remote control on and off switch properly labeled at helmsmen position, pumps should also be NFPA approved. With gasoline engines the bilge must be vented by USCG approved electric/DC blower motor in good working condition, vent duct work from this motor should be about 4 to 6 inches above the medium level of bilge water.  Sea cocks should be easily shut by hand should and emergency necessitates their closure.  Rusty handles should be replaced.  

The picture shows a sea cock with a handle shut off with a double jacked USGC approved through hull hose which is double clamped.  Note the wood back plate supporting the sea cock.

Venting the bilge.

Gasoline vapors are heavier than air.  Un like a car where gasoline vapors will float to the pavement and dissipate in a boat they will accumulate in the lower sections of the bilge.  This has the potential of a explosive bomb and with a ignition device will explode.  Many boats have exploded because of gasoline or gasoline vapors that have accumulate in this manner.  The bilge must be vented.  A mechanical blower NFPA approved must be operated 5 min prior to starting any gasoline powered boat.  This blower removes vapors from the bilge.  Blower duct work from this motor should be about 4 to 6 inches above the medium level of bilge water.  Their must be boat mechanical and passive venting of engine compartment and bilges.  All the duct work must be in good condition.  The blower motor must be fully operational. 

Hoses

Many types of hoses are found in the bilge.  Through hull hoses must be double clamped.  Through hull and water hoses should also be double jacket hoses.  Hoses should not have cracks and be in good condition, a leak in these hoses could sink a boat.  Engine exhaust hoses exhaust hose connections should be secured with two clamps at least 1/2 inches wide to each end producing a secure liquid and vapor tight joint.  Plastic and vinyl hoses are allowed only on domestic water systems.

Through hull fittings should be grounded by a green wire usually, to the vessel grounding system

All hoses in a vessels bilge must be examined.  Failure of these hoses will cause problems at the least and sink your boat at the worst.

Electrical equipment

All electrical equipment must be NFPA & USGC approved J1527 explosive proof.  All wiring should be color coded to indicate use.  Hard copper house wire is not allowed for use with AC systems & shore power.  All wiring must be stranded wire.  Wires should be neat and out of the way.  Battery cables should be secured at least every 18 inches and routed to avoid contact with metallic fuel system components, cables should be above normal bilge water levels throughout engine compartment and bilge. Both batteries should be secured against shifting. Batteries should be protected by a covered battery box. Ventilation should be provided that permits the discharge of hydrogen gas released by the battery. Battery shut off switch should be installed should DC power need to be should down quickly.  All wiring from batteries must be fuse protected.  Electrical wires should be soldered and shirked wrapped at connections or where joining wiring.  House hold wire nuts are not allowed they will rust.

Bilge Pumps

A variety of bilge pumps are available.  The larger the boat the more bilge pumps should be installed.   Bilge pumps should be working.  One or more automatic DC/electric submersible bilge pumps with automatic and remote control on and off switch properly labeled at helmsmen position, pumps should also be NFPA approved.  Some boats are equipped with a manual bilge pump (usually sailboats).  A manual pump is recommended should battery power somehow be lost.  Check the float switch regularly this switch is easily jammed and often need replacement.

Stuffing Boxes

Stuffing boxes let propeller shafts and rudders pass through the hull without leaking water into the hull.  They are packed with a packing material that resembles a rope covered with wax.  Stuffing boxes for rudders should not leak but those for propeller shafts require some water for lubrication.  Stuffing boxes can be tighten to slow down water leakage when packing material is present.  When all packing material is gone they must be repacked.

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