Sooty Transom

[Hydrozoan]

Does that mean that Cif is one of those implicated in polluting the oceans, in which case I will use it with great caution? I would never use it on shiny GRP anyway.

I was simply observing its mildly abrasive properties, and the calcium carbonate it contains – lots of that is precipitated naturally in the oceans anyway.

Warning noted but I have owned my boat for 20 years and cleaned the hull at least every year. Her previous owner had her for 8 years and it was he who told me that's what he used to clean the hull.

Fair enough; if the topsides still looks good, why worry? I just prefer not to rub away even small amounts of gelcoat if a detergent does the trick - and it also saves on elbow grease.