Well this post is generating some interesting discussion, and that is great
Sounds like you have thought this through Pete, and because of that you are probably not the target audience for this post!
You already knew BCA did membership for under 18s, had considered it and decided it wasn't for you - which is all very sensible.
However I get a lot of emails a year from people asking if a 14 year old can join BCA, if there is a lower age limit etc. I am not really trying to persuade cavers to sign up their kids - it is more a case of making sure cavers know they can if they want to.
3 under 18s have joined since yesterday, so at least a few people have found this information useful!
My role with BCA isn't just taking money for membership but helping cavers/ clubs understand it, and select the right membership types etc.
I agree claims involving small children are unlikely. 17 year olds who can drive themselves to caves maybe more likely.
BMC's biggest ever claimed involved students - so aged over 18, but not by much.
I also agree with you that the vast majority of caves I have taken my children to do not insist on BCA memebrship . Although I did think OFD did require BCA membership, and my kids have caved in there but I haven't been to South Wales in a couple of years so may I have remembered wrong or it has changed?
Apologises if my reply to your initial query sounded like I was trying to persuade you to sign your kids up. That wasn't the intention.
As this discussion is all on a public forum I was trying to answer your questions in a way that would be useful to others reading the thread.
I agree that BCA membership for under 18s probably offers more benefits to a 17 year old, than a 3 year old.
Essentially I am aiming to raise awareness so cavers can make an informed decision on BCA membership. Which you have already done, and your queries have led to more information on this thread, which is all useful.
As you pointed out BCA doesn't get many direct tangible benefits from more members under 18, so we don't have an interest in pushing it. We just want cavers to know it is easily available and free if they wish to make use of it.