The "Direct into Wind" model has now been fitted with a shroud around the rotor.
The shroud turns with the rotor and therefore is not a duct.
Fitting a shroud like this gives a few advantages.
It's partly in response to some
comments which express concern about the safety of rotating blades near the crew if
fitted to a fullsize boat and also has the advantage that it makes the whole assembly much stronger.
The performance of the unshrouded version was good.

Following tests at the AYRS "Broad Horizons" meeting, I found the performance was still
very good with the shroud in place, but maybe the wind needed to be more directly ahead than before.