I Asked a friend to measure my mast prebend, and it is only 2cm (less than one inch).

My mast is the original Nacra F18 mast 2005 (not wingmast), and the main is the original Performance sail (2006), topsquare 90cm (35 inch) approx.

A month ago I changed the two original top battens to softer; the original was 4kg (8.8lbs) the softer is 2.9kg (6.4lbs). The battens are in the pocket in order, not over tensioned, but stiff.

The other 2 teams sailed on the same tack, I was not pointing higher.

The other two teams are lighter then us, let say, 140kg (310 lbs), but just approximately

160 kg x 2,6 m = 416 << 140kg x 3,6m = 504

It is more than 20%

I have not seen too much F18 mast but mine looks really soft.

Traveller centered.

Mast rotator: in front of the dagger board a little bit. Later I tried with less rotator, because in this case the bending at the top of the mast became less (because the other axis of the mast).

Outhaul was tight, It was maybe a mistake.