Dart marketed their Dart 18 as
1 up or 2 up. (early 70's)

Basically... the Dart had a balanced rig which could sail equally well with or without a jib. (unlike the H16 or P16)
so... this was Dart's marketing spin.

So... they used the term 1 up... to refer to the Dart 18 with main only... Two up... meant the Dart 18 with two crew and a main and jib. In theory the two configurations were equal in performance.

Hobie 14's were always one up... ao no need for the qualifier.... 1 up.

Nacra came along and built the Nacra 5.5.... They marketed the hulls in two formats... Uni... taller stick and single sail... as the 5.5uni.... and a second config the 5.5sloop. shorter stick w main and jib.
The class rules speced that the 5.5uni was a 1 up... or single hander. The 5.5sloop was a 2up or double handed boat. Nacra never used the terminology of 1 up or two up and choose to stay with the rig description and imply how many sailors were on the boat.

Hobie then decided to add a jib to the Hobie 14 for the Rec sailors. ... they marketed it as the H14 TURBO.... (versus the Hobie 14 sloop.) the one up and two up designation... never really applied to the 14... since the hulls did not carry a lot of weight and the boat was not really raced.

The Hobie 17 got a jib and became the 17 sport... but again this was not a racing class and the one up or two up designation never really applied.

So... today.. the M20 or F18HT are called uni rigs since they have no jib... Yet both are double handed boats.
Recently, M20's have appeared with different rig configurations... each needing some modification to the class "M20".(extreme or Volvo 20)

The A class is a uni rig and single hander or 1 up... but since they only have one configuration... they simply use A class. no qualifier needed.

The F16, seems to use one up an two up... to refer to a uni rig with spin for a single person and a sloop with spin for a two man crew.

The Hobie FX one and Taipan 4.9 ... has all configurations going... eg single handed... uni rig (main only)... up to taipan with spin(unlimited spin) and then finally, Taipan F16 (fixed spin size) then you just add sails and crew for any combination you would like.

Portsmouth has always followed the class lead and lists the boat as the class would like in the table. Remember, the whole point of the listing is to make life easy for the Race Committee to get the proper rating for the competitor by using a class rule. Clearly, the system would be easier to understand if the builders and classes settled on one naming system and did not create a class for every possible configuration.

It would seem that you can designate the boat by characgterizing the rig. uni or sloop
and then add the spin if you want.

One up or two up then determines the crew numbers.

If you use a short hand form like a class distinction. eg F16 then you can use the one up or two up designation to specify which flavor of F16 you are using.


You still have the age old question... should the term "class' refer to a group of owners who sail a particular configuration... or should it simply refer to the boat configuration... regardless of how many individual members are sailing this configuration.