If it's grammatically possible, which I doubt, I double-took this morning on arrival at the boat park (our embarkation point for the island). It turned out that this fairly extreme disturbance off the northeast corner of the floating pontoons was caused by compressed air - therer's a diver down there, excavating under one of the concrete weights to which the pontoons are fixed, sinking it deeper by forcing the mud out from below with air-jets: since they were installed some years ago, the stays which go from the pontoons to the weights have lain at sufficiently shallow an angle to present an obstacle to keeled boats, and even to outboard motors, so all the weights are being bedded in in this way, with varying degrees of success depending on the density of the mud.
I can't imagine what it looks like from the diver's perspective - I certainly don't envy him this particular job!
