Oils, gasoline, and diesel fuel, when released into the coastal environment, are toxic to marine plants and animals. A poorly maintained engine or an accidental spill may cause these products to collect in the boat's bilge, and be discharged into the water when the bilge is pumped.

A bilge sock contains an absorbent material that will remove these petroleum products from bilge water. If your engine is well maintained, one bilge sock should last through the entire boating season. 

To use bilge socks:

  • Place the sock into your bilge. Secure the sock with attached loop (if available) to avoid interference with the bilge pump.
  • Check the sock at least monthly and replace when oil or an oily sheen can be seen in the bilge (which indicates that the sock has absorbed to capacity).
  • Dispose of used socks properly according to manufacturer instructions.
  • Check with your marina operator with questions about bilge sock recycling or disposal options at each facility; also check with your harbormaster about disposal options at public facilities.

Other steps boaters can take to keep coastal waters clean:

  • Prevent leaks by keeping your engine well tuned.
  • Keep your engine clean to spot leaks more easily.
  • Never discharge untreated bilge water directly into coastal waters. It's against the law!
  • Never add detergents or emulsifiers to your bilge—when pumped overboard they will degrade water quality.
  • Avoid spills—stay alert when fueling.
  • Do not top off your tank—fuel expands as it heats up.
  • Report spills immediately by calling (800) 424-8802. It's the law!
  • Do not use emulsifiers or dispersants (soaps) to treat a spill. It's the law!

For more information about bilge socks, contact:

Robin Lacey
(617) 626-1220
robin.lacey@state.ma.us