First, Sukhdev and the Bluefinz team, congratulations and thank you for making such a nice informative site. It is nice to be able to get a good vicarious fix when the water all around me is frozen.
The article on downhauling was great. I have used another type of rope that works better (in my experience) than Marlow Excel Racing. It is called "Swiftcord" and is made by Gottifredi Maffioli in Italy. 4mm is the preferred size. I rig with a Chinook crank and found that I was popping a downhaul every other day with the standard pre-stretch rope. Swiftcord is a braided mixture of Dyneema and cordura nylon. It is very durable because of the cordura, yet strong and low stretch due to the Dyneema. My most used extension, with which I rig my 10.4 Sailworks NX (which likes a TON of downhaul) has been rigged with the same downhaul line for 2 regattas and about 10 days of practice sailing. It shows no signs of wear.
I have no connection with Maffioli, except that I am friends with the US distributor, which is how I learned about it in the first place. If you are in the US you can buy it at
www.hallspars.com. I don't know where it is available outside the US.
Thanks and good sailing to all.