F-85SR Super Racer

There had been some interest received in regards to a design for the NZ 8.5 rule, and while I usually prefer not to design to rules, the 8.5 rule is a simple one, plus it limits rig size to where design and crew skills are more important than just brute power.

The F-82 is already a good performer under the 8.5 rule (race example), even though smaller and with a roomy cruising style cabin, so I took a little time to explore using the F-82 as the basis for a more race orientated F-85SR (for experienced sailors only). This will have longer hulls and a taller rig to fit the rule, and a cut down cabin, so it will be significantly faster again.

The F-85SR uses an extended F-22 rudder blade (using the F-22 rudder case), a deeper daggerboard, and it also has the F-32SR lifting foils as an option.

The F-32SR lifting foil – can be shortened and also used on the F-85SR

Standard racing cabin is a short cuddy cabin, but the standard F-82 length cruising cabin is optional. Float rudders will be optional, and float sterns are squared off to allow this, but I think float rudder are more complicated for only limited benefits, while all round performance may suffer.

The main advantage of the F-85SR will be the greatly increased performance over the F-82/F-25C, with its taller rig and floats that have a massive 600lbs more buoyancy. Plus it stills retain genuine trailerabilty (in minutes, not hours) and a roomy cabin, so it can still double as a cruiser (with care) when needed. It will be a tough boat, everything will work as it should, all of which will contribute to an excellent resale value once its racing days are over, plus it would be much easier to sell than a pure racer with no room.

L.O.A: 8.5m (27′ 10″)
B.O.A: 6.02m (19′ 9″)
Draft (foils up): 0.29m (11.4″)
Draft (Foils down): 1.89m (6.2′)
Height on trailer: 3.1m (10.17m)
Approx. bare weight: 1400 -1800lbs
(Depends on methods and materials)
Std. Mast Length: 11.28m (37′)
Std. Mast Height off water: 12.6m (41.34′)r
Std. Sail Area (main and jib): 42.37sq.m (458sq.ft)
Unlimited Mast Length: 12.6m (41.34′)
Unlimited Mast Height off water: 13.9m (45.64′)
Unlimited Sail Area – 47.84sq.m: (516sq.ft)

The Tall Unlimited Sail Plan

The F-85SR began as a concept boat, but there was enough interest to turn it into an available design. However, being very busy with the production F-22 and some other matters , the F-85SR has been a weekend task over the past year, but it was possible to start building, and plans have now just been completed (September 2012). The F-85SR lines (as DXF files only) are also complete and available.

DXF files can be used to print out full size patterns via a local Plan Printer, or, better still, used by a local CNC machine to cut out the form frames or bulkhead templates. This is the best way to make form frames now, even with older plans. Some full size paper patterns will still be included for the beams, and a few other miscellaneous items.

The first F-85SR as built by Multihulls Direct in the Philippines.
It then proved to be very competitive in the Race To Alaska.

A taller ‘unlimited’ rig with a 12.6m (41.3′) tall mast) is also optional, in addition to the standard 11.3m mast (that complies with the NZ 8.5 Rule). This has 515sq.ft. (48sq.m) of sail area and will turn the F-85SR into a potential line honors machine/screamer in any fleet. However, this tall rig version is intended for racing by experienced sailors ONLY, and is not suitable for family.

Clive Kennedy’s first F-85SR float joined….
and now with foam bow caps fitted, faired, and with primer