Cleaning the hull – what are these

I cleaned a portion of my hull and thousands of these small, wriggling things had to be washed from my skin, dive gear, and even ears. This picture is from my swimming shorts and doesn’t show their wriggling motion. What are they? I’ve googled a bit but haven’t found anything definitive. They are really irksome and I’m either going to have to get a wetsuit or hire divers to clean the hull.