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Course Outline

MSD at pump-out station

If you have a recreational vessel with installed toilet facilities, it must have an operable marine sanitation device (MSD) on board.

  • There are three types of MSDs.
    • Type III MSD, the simplest and most common, consists of holding tanks or portable toilets. It requires only a small storage space and is simple to operate. Type III MSDs have the least effect on the environment because the waste is to be discharged on shore into a local sewage treatment facility.
    • Type II MSDs1 are required for vessels 65 feet and longer and use a combination of maceration, septic treatment, and chemical treatment to kill bacteria just prior to discharge. There may be a Y valve that directs untreated waste material for discharge or directs waste material for treatment prior to discharge. The Y valve must be secured to direct waste to the MSD.
    • Type I MSDs are for vessels over 26 feet and under 65 feet long and use a combination of maceration and chemical treatment to kill bacteria just prior to discharge. There may be a Y valve that directs untreated waste material for discharge or directs waste material for treatment prior to discharge. The Y valve must be secured to direct waste to the MSD.
  • All vessels 26 feet or more in length that have an enclosed cabin with sleeping facilities must be equipped with a toilet if on Florida state waters.
  • On a vessel other than a houseboat, the toilet may be portable or a permanently installed toilet properly attached to a MSD.
  • Every houseboat must be equipped with at least one permanently installed toilet properly attached to a Type III MSD.
  • All installed devices must be USCG–certified.
Typical MSD
Pump-out sign
Signs like this one are posted at pump-out stations.

1. There may be a Y valve that directs untreated waste material for discharge or directs waste material for treatment prior to discharge. The Y valve must be secured to direct waste to the MSD at all times within Florida waters (three miles or the edge of the Gulf Stream, whichever is greater, off the Atlantic coast or nine miles off the Gulf of Mexico coast).

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