Thanks for taking the time to search, there
is a large cube block that juts out of the bottom of the structure in the distance that I have to also eliminate from enquiries (to do the job properly)although if you saw it, you would see it's completely at the wrong height for the angle to confuse it with the small blob at head height in the above picture .. nonetheless, that block is there in the distance and perhaps the lighting could have caused an illusion ?.. I'm going there now, the Mrs has said "Sod it! .. let's go back!" .. so back in a bit
..
edit: just got back and we're satisfied it's an illusion created by the low down block in the distance only visible at low tide that appears higher (exactly at the spot in the above picture in fact) when taken from a higher angle .. we're sure we've taken a pic tonight from the same spot the above picture was taken, the only difference to the above picture is that our picture's 'blob' shape taken tonight has obvious square angles. I think a combination of the waves and the lighting did the rest in the above picture to create the illusion of a more rounded head shape. Oh well, it was fun while it lasted.
Sorry for not uploading this evening's evidence pics tonight, I'm up and down on these pain killers so taking it easy instead.