Hi Paul and Malcolm

It's the persistant tech freak again :o)

I have been looking at the video a lot and been reading your description (a bit more detailed this time) and:

Thesis: The boat did not flip because the foil broke, but the foil broke as a result of extensive load in the initial phase of the flip.

Arguments: When you look at the video, a wave causes the bow to make a small jump. This small jump exceeds the limit for the balance of the boat, and the the bow starts to rise as a result of the lift from the increased angle of attack on the main beam. At some point all the horisontal load on the mail foil is situated near the tip resulting in extreme momentum at the base of the foil, which then snaps. The boat then completes the flip. During this it is bearing off quickly as a result of the missing horisontal grip from the foil. At the point where the foil snapped, it was in my opinion all over.

Anyway - take my input for what it is - it is very difficult to sit at this distance and be a smart (ass), but on the other hand, it is always nice to see different approaches to analysing a problem.

Back to my proposal of a regulated system: Malcolm, you mentioned the danger of having the "sensor ski" mounted near the bow, as this would have generated the exact opposite input to the system in the "wave incident". This is of course true, the "sensor" should be on the trailing egde of the front planning surface - or could even be the complete front planning surface, if this was hinged at the front.

Regards and best wishes for the continued WSSRC period

Flemming

On the video sailrocket vs hydroptere I saw a strategically filmed model that looked different from your first blue one. Makes me very curious !!
Are you experimenting with another model ? Can you reveil more or is this all very secret still.

Cheers

Johan