Class Rules Question - "cabin top"

[Warren Nethercote]

Class Rule 2.5 says "Fair curve of cabin roof adjacent to the mast step or partners shall be no less than 35" (889mm)above the bottom of the hull at station 89."

Nowhere do I see (but I may have missed it) reference to a separate, above-deck cabin structure in the (Version 2, 2014) class rules, but I did see a discussion in the forum about a requirement for one. A cambered foredeck should be easier to build than a cabin, and is one of the options on the Waterline site. Wearing my naval architect's hat, the cabin is the internal space, and a cabin roof is satisfied by either a cambered deck or a 'coach' structure above. But my preference for the simplicity of a cambered deck (assuming that the 35 inch criterion can be satisfied) is for naught if the official measurer's interpretation is that 'cabin roof' is the roof of a coach structure.

So, is an above-deck cabin structure ('coach roof' to some) a requirement of the class for one-design racing? Clearly, it matters not at all for a play-boat, but one always hopes for come one-design competition, and taking an i550 on a road trip would be no big deal.

Warren Nethercote, Nova Scotia
Thinking about a successor to my Soling ......

[ryderp]

Version 2 of the rules was intended to help unify the different versions of the i550 class. You can definitely use a cambered deck, or a low profile cabin, or an original height cabin.

Phil

[Chad]

Yep, whatever covers your cabin space, near the mast step, be it "deck" or separate "coach roof" structure, needs to comply with the height rule.

The rule is designed to keep some kind of cabin/usable interior space as part of the Class rule, and to put the same restrictions on everybody in terms of crew ergonomics (the cabin/foredeck also limits the forward extent of the cockpit). For racing, a cabinless, open "dayboat" style offers lower cg and easier crew movement. But it puts all the original builds at a disadvantage, which is less OD than our Class has decided is acceptable.

-Chad, measurer.