DRAGONFLY Trimarans User Forum

I have noticed when out sailing in company with other DF920s that our boat (#35, a 1998/9 cruising version) appears to sail much flatter than others. Other boats appear to have the amas (swimmers) higher than ours, so that in around 15kt of apparent wind their windward ama is out of the water. On our boat, the windward ama only comes out of the water with over 24kt of apparent wind close hauled with full sail.

We set the waterstays according to Arne's recommendations (when ashore and with the amas mounted, move the amas back about 30cm and then adjust the length of the waterstays until you can just instal the clevis pin).

Should we slacken off the waterstays so that the amas are higher? I would like to do this so that we get less drag and more speed, but not at the risk of safety or increased maintenance.

Any suggestions appreciated.

One must keep in mind when adjusting the water stays, that the boat is typically out of the water and the amas are without support. Gravity takes out 100% of the slack, so there is nothing to be gained by adding stress to the structure (pulling in the downward direction).

With that in mind, my goal is to remove all slack from the water stays, without putting them in tension. The way to accomplish this is to adjust them to a point where some slight increase of resistance is felt at the very end when opening the amas all the way, then back off 1/2 turn on the adjustment.

You will find that this will keep the water stays without visible slack, but allow you to deflect the cables slightly by hand. From that point, it is a question of feel and judgment, trying to get the tension even between fore and aft water stays. If you think there is a quarter-turn decision to be made between balancing both fore and aft, go with the slightly tighter setting. You don't want them to go slack.