I disagree with John, The demise of the 20 footers is not due to it being a dick forest or skewed to heavyweights. The T class (optimum team weight 325-340lbs), N20 and N6.0's are members of the dead boat society or zombie boats for more profound reasons.

There is power in calling your shot (just like pool)

When you call your shot... you set up and expectation. When the class delivers on the expectations... the Class sailors are very happy and they come back for more....
If you just leave it to chance... you just don't get the same feeling when you get 10 boats to a race by chance(we were lucky?) .... you certainly don't have anything to count on for the next event in the region.

For example,
The F18 CLASS calls their shot and declares they will have a regional championship (Southern Championship at Spring Fever) for their fleet. They have a North East championship and a circuit in New England.

I listen to the questions that Hobie Sailors have for me about the A class. Those guys go racing and they know what to ask about a class. Since they count on the other Hobie sailors in their class to go racing and turnout for the agreed on schedule, They want to know... How many A cat Events? Where is it published? Where are they? and What is the turnout? Who is racing the boat? Is the class national or regional or just local? Who is the local class guru that could offer some advice in getting into a boat and the class? The track record matters... the more often we deliver and meet expectations the stronger the class actually is. The more often we hit the mark... the more attractive the class is to racers.

Look at the Hobie 16 Class. They have been successful for years and years for a reason. They publish a schedule, score high points, etc and do lots of other basic stuff known to be essential for a strong class. They do a great job of calling their shot and getting the information out there. Their racers know that they are in the class together and commit to their schedule. In my area, on average almost 3/4's of the 16 class turn out for the schedule they agree to. If you are a Hobie 16 sailor you are never upset that your class did not post for the regatta that you spent time and money on attending.

Racers buy a boat so they can compete in the Races (distance or buoys) they like and the regattas they want to go to and compete against others in their class (handicap or OD). Nobody is going to buy a toy without a great deal of confidence in where and how much you are going to play with it.

JW commented that the N20 class was a dick forest... The A class is just as male.. and that has not been a problem for growth.

JW commented that the crew weight requirements were high and implied that this was a problem. Well, the Hobie 16 crew weight requirement is LOW and that hasn't been an unmanageable issue.

If the 20's are loosing ground to F18's, then the 20 fleet needs to really market their perceived niche and do a great job on the basic class stuff.

The basics of a sailing class are universal. The virtues of the N20 platform are almost irrelevant if you don't get commitment on the basic class stuff.

(I bailed on the Tornado (the best ride I have ever sailed) when the class members failed to commit at the local level.. (8 boats at one time max turnout once of 4 boats) and when the schedule became 3 events in the USA (miami, Houston and the west coast) and no interest in coordinating with the N20's on a racing schedule.)