by GreenLake » Sun Jul 09, 2017 11:36 pm
When water just gets over the rail, that's not that close to the point where you lose control in a capsize with a DS. For a DS1 at some point past that you can get serious volume of water in the cockpit and cuddy, which would affect stability negatively. For a DS2, with its double hull, I would expect the effects to be less dramatic. I've had water up to the coamings a number of times on my DS1 and it did not result in capsize.
You are correct that you will sail faster when you sail flat, but not always. The exception is very (!) low winds, when heeling the boat can reduce the skin friction (by reducing the wetted surface). Heeling the DS to leeward in those conditions also helps the sail shape (gravity will help "fill" the sail when the wind isn't strong enough).
The different components to drag each have a different speed regimen at which they dominate (are the biggest contributor to total drag). Skin friction dominates at low boat speeds, wave drag dominates at the top end.
If you can get the DS onto a plane (see discussion of planing elsewhere on this forum), you can reduce the effect of wave drag dramatically and sail a lot faster. Not really possible upwind in a DS, but you should be able to get there on a reach. For planing, you want the area at the back of the boat flat (that's how the DS is designed) and parallel to the water's surface (i.e. also sail the boat flat).
Below planing speeds, sailing the boat flat should also make it (somewhat) faster, but unlike the transition to planing the difference isn't as noticeable; you may need to have another boat to compare yourself to, to see it.
If you have a GPS (or an app that records speed), if you get above 6-6.5 knots you would be planing. (The wind is too variable to make a GPS a reliable indicator of small improvements - a DS reacts too fast. On bigger boats, that react more slowly and therefore "average" some minor fluctuations in the wind, you can sometimes see the effect of some trim change in the GPS speed).
Sailing more flat, a little less "on edge" should also give you a bit more reserve if you are hit by a sudden stronger gust.
If you have a vang and it is a 3:1 or 4:1 upgrade it to something more powerful (12:1 or more). Use it to flatten your sail, use outhaul and, if you have it, cunningham for same. With the sail kept flat by the vang, let out some mainsheet to depower (if you let out just the sheet, the boom will go up, make a deeper sail shape and power up the sail when you don't want that).
And, if you like this kind of sailing, fit hiking straps so you and your crew can hike hard to keep the boat flat.
~ green ~ lake ~ ~