Gary,
it looks like you got your wish and kicked off a lively discussion.
The bottom line for you is to increase your membership. Appreciated, and from the answers you've got, you made at least a few "sales" this round.
What can you do to make this more effective?
I would start with the bylaws of the organization. If you want non-racers as part of the DSA, make it official in the formal objectives of the organization. That gives the activities you do in support of cruising less of a feel of an afterhtought. Likewise, put the association's relation to DSIII owners on better terms. As you can see on this forum, the same individuals may be associated with more than one boat type. (As the DSIII is no longer produced, there's no reason to fear dilution).
I would encourage you to extend the material about the DSA that is visible to visitors of your website. As it stands, someone practially has to join to find out what the organization is doing beyond scheduling of races.
For geographically dispersed individuals you offer the "independent fleet". My immediate reaction was that this is a contradiction in terms. A fleet defines a local community - by definition, the independents do not have a local community. My next reaction was to wonder what, if anything besides a convenient book-keeping bucket, might be going on in terms of acitivities in that "fleet". (Incidentally, I share K.C.'s doubts about the newsletter as a major benefit - but obviously that's "sight unseen").
I'm approaching this from taking you seriously in your statement that the DSA values independents (and non-racers). To me, it appears that, before this discussion, you and others simply haven't communicated that very well to anyone coming at the organization from the outside. Your efforts to recruit additional members will probably become more successful to the degree that the DSA becomes more transparent in these areas.
Perhaps the best thing to offer independents is simply the virtual community represented by this forum. If that's the case, the radical conclusion would be to redefine the independent "fleet" as centered on this forum and run it on voluntary subscription basis with regular "invitations" to sign up.
I can't find a conclusion better than K.C.'s closing statement:
I see the DSA forum as likely the best promotion for this boat and the class. Having benefits made apparent through this forum would be a good way to promote a membership campaign, I would think.