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First 235 Polars & Comments
This is a Beneteau First 235 polars drawing done by Greg Lundstrom.

Beneteau First 235 Polars

The picture below was from the 1987 French Magazine review of the Beneteau First 235
See translation of review comments below

Polars and Technical Opinion - Discussion

The Technician's Opinion

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.

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