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WOW - Conner Blouin: Downwind Sunfish Sailing

12/23/2022 6:13 pm

Conner Blouin WOW: Downwind Sunfish Sailing

Posted December 23, 2020


The first step to sailing a Sunfish well off-wind is getting the proper heel and pitch. The chines and rocker on a Sunfish make the boat much more forgiving in these areas as opposed to a laser. Chine refers to the sharp edges on the bottom of the boat, and the rocker refers to the curve in the boat from bow to stern. The chines make the Sunfish less likely to tip over when heeled over in any direction, and the rocker makes the boat less likely to drag the bow or stern through the water if you sit too far forward or aft.


Any time you sail downwind, a boat will want to sail in a straight line, when the Center of Effort (COE) is aligned with the Center of Lateral Resistance (CLR). The COE refers to the deepest strongest point of the sail, and the CLR is more or less your daggerboard. When the two are not in alignment, the boat will want to turn into the wind or away from the wind, and you will need to correct with the tiller, creating drag. More specifically, when you heel too far to windward, the boat will want to sail down. When you sail too flat, the boat will want to sail up into the wind. When you round the top mark in a Sunfish, and ease the sail, the COE and CLR spread really far apart. This is rectified when you heel the boat to windward, until your tiller feels no resistance sailing in a straight line. If you ever want to check yourself on how much heel you need, simply look backwards and see if your tiller is centered.

Sailing dead downwind in any boat is typically inefficient. Preferably, you would like wind to flow across the sail, as opposed to simply pushing into it. If wind simply pushes into the sail instead of flowing, the wind stalls on the sail, and you slow down. When you sail downwind in a Sunfish, you have two angles of sailing, your reach angle and your by the lee angle. The reach angle is defined as when the wind flows from luff to leach on your sail. By the lee is the inverse, when the wind flows from the leech to your luff, ostensibly reversing the roles of each edge of your sail. The issue with sailing at the reach angle in the Sunfish is that you don’t have a working vang to adjust your leach (as you would in a Laser). This creates the need to either have your vang set up appropriately for this angle, or to steer to the angle to get your leech shape correct. For example, when sailing with not enough vang, the gooseneck will go up the mast, and spill the wind at the top of the sail. In certain wind conditions, it is a challenge to have your vang set up properly with no need for adjustment. Thus, all things equal, this is not ideal on most single handed boats, as you must increase your vang as wind increases to maintain the appropriate sail shape. It is important to note that due to the Sunfish not having an adjustable vang, you have to make these changes by steering to the appropriate angle to achieve the proper sail shape. 


With by the lee sailing, the luff of the sail ostensibly turns into your leech. On this end of your sail, the upper boom keeps the sail firm as wind exits, so minimal vang is required to achieve the proper sail shape. Thus, all things equal, by the lee sailing is more efficient. However, both are necessary in almost all wind conditions, and having both in your arsenal will make you a stronger downwind sailor.

Once your heel and sailing angles are dialed in, getting your pitch right will help you jump to the next level. If you sit too far forward or backward in any boat, you will drag either the bow or the stern through the water, adding a good deal of resistance and slowing you down. In light winds and flat water, sitting forward and just aft of the daggerboard is ideal. As wind and waves increase, you will want to scoot further aft to keep the bow of the boat from pushing water, and to either allow the boat to get on a plane, or expose more surface area of the hull to waves for surfing.


Once you have all of these fundamentals added into your downwind arsenal, it’s time to think about managing or surfing waves downwind. There are three modes that involve waves downwind. These include wave hopping, full surfing, and partial surfing. Wave hopping in a Sunfish is rare, and occurs when the waves are small to medium in size, and there is enough wind to get the boat up and over a wave. This generally means you have enough wind to get the boat onto a plane. Good examples of this will include the second day of Sunfish Worlds 2014 and the last race of 2020 Sunfish Nationals in Mississippi. Wave hopping will work the best on starboard (as the sail is more full), and on a reach angle with your weight back a bit. Your angle downwind should be high enough to get on a plane. This is easier on a reach angle than sailing by the lee. As you are planing and hopping over waves, it is important to occasionally invoke some partial surfing technique (discussed later), and head lower as long as you maintain the boat on a plane. This will keep you more centered on the course.


Full surfing is possible in medium to large waves and swells, and medium to heavy wind speeds. In this surfing condition, your goal is to stay on the wave as long as possible. (1) In most cases, get the boat going as fast as you can at an aggressive and hot reach angle. It will feel like you are sailing well away from the bottom mark. Your goal here is to generate as much speed as possible to lock into the wave. As a boat surfs waves for extended periods of time, the changes in apparent wind (wind your boatspeed creates) make it nearly impossible to stay on waves at a reach angle. Thus, starting on a reach angle is a must, and will help you stay centered on the course. (2) As a surfable wave approaches, lean or move back and heal the boat gently to windward with a small ease in the sail to steer down the wave (easy part). This will enable the boat to turn down with minimal rudder usage, while keeping the bow from pushing water and exposing the stern to as much of the wave as possible. This is where things get complicated. (3) At this point, if you have caught the wave, you will want to steer further down to surf the wave at a diagonal angle, traveling across it horizontally (much like any surfboard video you’ve ever seen). If you do not, you will either rapidly surf forward and fall off the wave, or run into the wave in front of you (or both). In doing so, you may heel the boat over slightly more, switching from a reach angle to by the lee. At this point the wind is moving across your sail in the opposite direction. You may need to trim the sail slightly. (4) Before the wave moves past you, turn the boat back to windward slightly by flattening it out and trimming in the sail. This will cause you to surf forward, further downwind. Take care that you do not fully sail into the trough in front of you, and instead, repeat step 3. Repeat steps 3 and 4 until you lose the wave. Err on the side of outrunning the wave as opposed to it outrunning you, so you may more easily return to your reach angle and repeat the process. This process is most commonly known as an S-Curve.


The final downwind surfing mode is partial surfing. You can employ this mode in almost any wind condition or wave state, but is most common in light to medium winds and small to medium waves. The technique is more or less the same as in full surfing, but without switching from reaching to by the lee, or vice versa. Instead, your goal is to use the waves to help push you forward incrementally, while keeping your apparent wind as far forward as possible over extended time periods. (1) To start, get the boat sailing quickly at your reach or by the lee angle. Pick whichever angle gets you onto waves most easily. (2) As a wave approaches, heel the boat gently and turn up or down the wave. Make certain that you do not turn too far, and switch the direction the wind is flowing across the sail. Heel and steer back to your original position to get ready for the next wave. Rock your shoulders aft in light to medium airs to expose more wetted surface to the wave. The most common mistake made is turning onto a wave and trying to hold the new angle for too long. This will cause your speed to drop and you will have to sail a very aggressive angle to start the process over. If you head back up or down, while you still have residual speed from the wave, the decreases in your apparent wind are more mild, and will not require as much change in your angle to regenerate.


Downwind sailing in any boat can seem overwhelming at times, but there is no substitute for a little practice and chatting about it with your friends!