Tidal affect and logistics on Bay Downwind Runs

Regarding what causes the wind over tide effect, it seems to be pretty poorly explained in general, this is a nice visual theory - basically the flow causes waves to converge. Generally all quite interesting - see a discussion here where some theories are thrown around.

What remains unclear is why you can’t hydrofoil bumps in less than 10ft depth?

There was loads of interesting info in the Matt Costa interview for anyone who is interested in a deeper dive into the general phenomenon of what causes waves