I am sure that if Bavaria and other manufacturers had discovered and used material for through hull fittings that was better than being reported in the yachting press, by now they would have responded to the criticism being placed at their door.
    It is therfore probable that all our through hull fittings are made of brass or a brass alloy that will last at least five years, but may then fail at some time in the future. The length of time to failure cannot be determined as it depends on the rate at which the metal errodes due to electolitic action, causing dezincification. There will be no visible sign of a problem, as the errosion will take place, starting on the inside of the skin fitting, ( the bit in contact with the salt water). The sea cock itself will probably be OK as these are quite often just above the waterline, except for the engine raw-water inlet.
    The only visible sign may be the brass turning to a copper colour and this may become apparent on the outside of the skin fitting. Hitting the fitting with a hammer may not cause the fitting to break, but could cause a fracture that would speed up the time to failure. As failure is likely to be between the locking nut on the dry side of the skin fitting and the underside of the seacock, this would result in major water ingress and the possible loss of the yacht.
    This whole problem is being given major campaign status by the yachting press and I for one am taking it seriously. It would not surprise me if our insurance companies start to place demands on replacement periods, just as they do with standing rigging.
    The fact that many of us have reported that we have owned our boats and used them for 9 years without a problem does not confirm that everyones boat will do the same. If by chance a boat has been kept connected to shore power and has experienced problems from electrical leakage, then its through hull fittings could fail sooner than the periods reported.
    It is the uncertainty that is worrying which is why I am going to include a thorough examination of all through hull fittings on my annual maintenance list.