Just read a great article in SAIL magazine by Peter Nielsen regarding the SDR and C1500. It's called "Group Think". Here's the takeaway:
The C1500 organizers, with their European risk-management-style insistence on strict safety protocols, started their rally a day early, on the weather router's advice, to beat the two fronts bearing down on the Chesapeake. The Salty Dawg people, whose rally was founded in response to the rigid safety requirements of the C1500, take a laissez-faire approach that places the onus for preparation and decision-making on the individual skippers. Rightly so, you may say, and I would usually be the first to agree, as the ultimate responsibility for a boat's safety rest squarely on the shoulders of its captain.
But of all the reasons to join a flock of other boats in an organized blue water rally, surely the notion of safety is one of the strongest. I suspect that the passage that lay ahead of the skippers in the Salty Dawg and the C1500 would be the longest most of them had undertaken, and faced with the unfamiliar, there is certainty of comfort in company, and at least the illusion of safety in numbers.