The vertical bow of the F235 is
certainly the most original part of the very pleasing
hull. A well-immersed sternfoot gives the F235 a fake
mini-Transat look. The beam is situated far aft and has
been limited to 2m50 to allow for road transport. Less
wide and with a smaller sail surface, the F235 is of course
not as powerful as the Transat racing boats. The forward
sections are quite full, compensating the absence of a
peak. The aft sections have a very flat bottom and the
bilge curves inwards above of the waterline. The freeboard
height is quite modest, especially aft and despite the
aft cabin layout. The flat bottom has a clear influence
on stability: as soon as the bilge is totally immersed
stability increases dramatically. One will rapidly heel
to 10º or even 20º, but a wind speed of 19 knots
is needed to heel to 30º.
With large sails, a genoa that is
larger than the mainsail, a very long waterline and a
relatively small wet surface, the F235 performs well,
especially in light winds. All our tests and computations
were done with the fixed keel version. A retractable keel
and rudder can reduce the draught to 70cm if required.
The polar diagrams show that
the best VMG will be obtained sailing close to 45º.
Performance for 10 and 20 knots are roughly equal as demonstrated
by the VMG diagram. The best VMG (at 3.55 knots) is achieved
at 17 knots with a heel close to 30º and two reefs
(sail reefed by 25%). Close hauled sailing and tacking
will be quite difficult with winds over 20 knots, and
the VMG decreases steadily to 2 knots at around 40 knots
of wind. The polar diagrams also show us that one might
just as well sail straight abeam when going downwind,
especially in light winds. For instance, the best VMG
by 5 knots wind is at a 155º route.
The top diagram shows the VMG for
various wind speeds. It shows that at winds of 18 knots,
it is recommended to reef the mainsail 25%. When the wind
hits 26 knots, reef the main 40%. The First 235 will heel
to 30 degrees by 20 knots wind.