Treads!
Chris Draper was a family friend and on a Christmas ,] in the mid 60's stayed with us and showed us the film taken from inside the Auster ,Chris reckoned that ,quite safely he could have taken a formation of three up the river .what is not recorded is that he skipped over those bridges that he considered in any way a bit dicey.
To sit and and talk to a Camel pilot was a rare privilege for a 16 year old !