Stuck in the sands

.... of the Gironde estuary.
We came across these wrecked vessels laying in the sands of the Gironde. They have obviously been there for many years, but I could not find anything out about their history or how they came to be there. Perhaps they were just redundant barges which were sunk deliberately and left to rot?
I thought there were two of them, but upon looking on google maps, there are three. The google maps image is inset into today's extra.