Hi Gordon
Your emails are getting through OK. I think the trouble is that nobody wants to volunteer. I've never had to do a risk assessment, but I think Oci is probably not far off the mark. One thing that might go down well in a risk assessment is to have specific duties allocated. For example we may have a "task master", or would he be a "cox" perhaps, whose job is to coordiate the rowing. That would reduce the risk that one person suddenly ends up with all the weight and gets flipped up into the air by his lever.
I know a broker who specialises in public liability insurance. I'll have a word with him. He should know what's required by way of a risk assessment and also, perhaps, which companies would be best to approach for cover.