I think you'll find that with the good(ish) swell and high tide on Sunday it stripped back a bit of the sand from the beach exposing an older level of beach. This sometimes looks like oil but is only dust and dead plantsor seaweed which onde wet looks like a black residue. On Monday the beach at Watermans was much steeper than in the past and some of the rocks near the rotunda have been exposed..... better everyone stay well away[}:)]

AB.....