This recent video from Justin Mitchell shows Ineos Team UK testing another foil format on Britannia.
The video captured on Sunday shows Britannia coming in from her day out sailing, mainly out of view from North Head, around Race Course E.
They were sailing with the port foil changed back to a straight anhedral wing, with wing tip.
While the starboard foil was the cranked wing foil developed by the the F1 Applied Science team that they have used since the launch of Britannia 2.
Ineos used straight foils on their first version of Britannia, but launched Britannia 2 in Auckland with new cranked foils . . . one-side with a wing tip and one without.
They now seem to be running a direct comparison between the straight and cranked foils.
In the second half of the video they tacked and sailed for some time with both foils lowered, although the grinders appeared to be working hard and there was also some considerable crew movement.
Almost as if they had a problem getting the foil arms to function?
There has been comment recently by Luna Rossa that there was still a problem with operation of the foil arms, which are supplied items.
Luna Rossa skipper and CEO Max Sirena is reported to have described the foil cant hydraulics system – produced by TNZ – as not matching the quality of the foil arms, and has said the other teams have also complained.
This is despite the foil arm hydraulic system having been revised for the second boats after earlier complaints of operating problems.