Saturday, January 14, 2012

A comparison of speed strips

Too sore from getting beat up by 58 mph gusts yesterday, and too wimpy to sail today in near-freezing temperatures, I decided to look for reasons why no speedsurfer around here has gone much faster than 35 knots - while in Europe and Australia, hords of windsurfers are going faster than 40 and 45 knots all the time (and recently, a few have broken 50 knots).

For wannabes like myself, we can explain the low speeds by lack of skill and proper speed equipment. However, at least 3 of the guys on our Fogland Speed Surfer team are kick-ass windsurfers with extensive race and/or teaching and freestyle experience, and they all have gear that can easily go 45 knots. So what to blame then? Maybe the lack of proper speed spots in the area? 

I decided to have a closer look at our favorite spots, and compare them to West Kirby in England, where several speed surfers have broken 50 knots already this year. For the impatient readers, I'll start with a table that summarizes the results:
I'll briefly explain the different columns before I discuss each spot in detail.
Access describes how easy it is to get to the speed strip; ideally, we want to drive right up, carry our gear a few meters, and then race downwind at full speed.
Depth categorizes the water depth at and near the speed strip. Shallow water keeps the water surface smooth and fast, and can eliminate the problem of having to waterstart ridiculous large sails with huge mast sleeves full of water in very strong winds.
Tides show how sensitive a spot is to the tides; some spots are only fast at high tide, or may not be sailable at all at low tide.
Length is the length of the speed strip that can be sailed at the ideal angle. A 10-second run at 50 knots covers about 260 meters, but we need to add space to get up to speed and to stop.
Barrier relates to the jetty, sand bar, or similar obstruction that creates the perfectly smooth water for speed runs just behind it. 


Let's look at West Kirby first. The West Kirby speed strip is in a man-made "marine lake" that is 5 feet deep. The speed runs are made at a wall that rises about 4 feet above the water levels; the speed strip is about 620 m long, with extra room at the start to load up for Slingshots, and at the end to jibe. The low barrier wall can be walked, which makes it easy to walk the gear back to the start. The wind has a clear fetch for several miles across a bay before it hits the speed strip.

West Kirby is one of the fastest speed strips in Europe. Just 11 days ago, several speed surfers broke the 50 knot barrier there. So a speed strip length of 620 meters is definitely enough; for 40 knots, even 500 meter should be sufficient.
Next, let us look at Fogland bay in Tiverton, Rhode Island, the birthplace of the Fogland Speed Surfers. The entire bay is about 500 meters across, and quite shallow. Tides in Fogland are about 4 ft, and most days, the speed strip shown in the picture is sailable the entire time (at least with short speed fins). Only when tides drop below normal low does the ground start eating the fins of speed surfers who venture too close to shore.
The best wind direction for speed in Fogland is SW to WSW. There is a second speed strip going up along the shore that is about the same length. However, both strips suffer from gusty winds since the barrier here is higher (at least 5 feet at high tide) and more uneven than at West Kirby. A bigger problem for 10-second top speeds is that the runs are quite short - a 340 m run like indicated by the line in the picture above would require a very abrupt stop at the end. All this makes Fogland a great place to get started with speed surfing, or to go to when it's so windy that some extra safety becomes important - but breaking 40 knots there will be very hard, if not impossible.

The next spot to look at is Duxbury bay. Similar to Fogland, it is separated by a sand bar that is wide enough to include a road. Tides in Duxbury are about 9-12 feet, which affects windsurfing: at normal low tide, most areas in the bay are too shallow for windsurfing. Even in between tides, the lower water level increases the height of the barrier by about 5 feet, to a total of more than 10 feet, which disrupts the wind quite a bit. This is less of a problem closer to high tide, but then, the water about 50 feet from shore is more than 10 feet deep. This means that in theoretically ideal N to NNE wind directions, a lot of wind swell builds up, which kills top speed.
However, Duxbury is by far the best local spot for long distance speed (one hour, nautical mile, and total distance). In ENE to NE winds, runs are almost 5 km long. About 50 to 100 m from the shore, the effects of the barrier are negligible, and the water is still very smooth in light to medium winds. Doing 100 km here means going back and forth only about 11 times!


The next speed spot to look at is in Hyannis Port Harbor: the Kennedy Slicks. A stone jetty protects the harbor from the prevailing SW winds, and creates a 560 m long speed strip. The ideal wind direction would be W, but west winds come across land therefore are weak and gusty; the best wind direction that actually works is WSW. Tides are about 4 feet; at high tide, the top of the jetty is about 4 feet above the water level. That's almost perfect - but unfortunately, the first half of the jetty has a number of large holes, through which waves crash at high tide, creating small waves and limiting speed.
To sail at the fastest angles (120-135ยบ) in WSW winds, it is necessary to sail away from the wall. However, since the water in the harbor is pretty deep, the chop builds up very quickly, which again limits top speed. The Kennedy Slicks are a great place to play and practice, but reaching 40 knots here will be very hard, even if the tides and wind direction are perfect.

This brings us to the last local speed spot that we'll look at, the Egg Island Slicks. This spot is less than 2 miles from the Kennedy Slicks, on the other side of Kalmus Beach in Lewis Bay. While I have sailed the other local spots many times, I have sailed the Egg Island Slicks only once - and broke all my short-distance personal bests that day. Egg Island works best in SW winds, where it offers a 500 m long speed strip right next to a sand bar that is just barely above water at high tide. At the end of the sand bar, the chop increases gradually, enabling a controlled stop or turn. The wind tends to be a bit gusty at the start of the strip due to the "Great Island" below, so very small speed boards could be a problem. However, the setup allows a Slingshot approach from the right, and there is plenty of shallow water nearby to stand and rest.
The one drawback that Egg Island has is that it requires an approach over about 500-800 m of open water, which includes crossing a ferry lane. The waves and chop during the approach can be challenging; they were completely doable on a 30-35 mph day, but could present a real problem on a day like yesterday, where average were in the 40s and gusts in the 60s. Those are the days when real records are set...

Well, I think we can safely conclude that we cannot really blame the spots for our local low speeds. I think the problem may be more due to lack of "critical mass". With that, I don't mean body mass - Steve Thorp has shown that you do not need to be 6 ft tall or weigh 200+ pounds to break 50 knots. Rather, I mean number of speed surfers. Single speed surfer teams from Australia may get as many as 20 surfers onto the water on a given day, with 7 of them posting speeds near or above 40 knots; in the Netherlands, speed strips may see 100 windsurfers on a good day. Around here, I am happy if there are 3 of us on the water going for speed, and 5 makes a great day. But every time I get to sail with our better surfers, I learn a lot, and if we have good wind, I usually break a personal best or two.  In addition to the learning, bigger groups increase the stoke factor. For example, in surfing hot spots like Australia or the Netherlands, it is quite normal to take long boat rides, drive a few hundred miles, or even do 2-day trips by plane just to get to the right speed spot at the right time. Our little group may not be as big or as crazy about speed surfing yet, but we have seen a number of group sessions, new speed gear, and plenty of new personal bests in the last year - and I am sure 2012 will be even better.

1 comment:

  1. "So what to blame then? Maybe the lack of proper speed spots in the area?"

    The spots you listed look great, I would hazard a guess and say equipment is the problem. You need some powerful cammed race sails, some mid size speed boards and decent fins. Then spend lots of timing tuning and getting used to the gear. TOW is the key to good speeds in any conditions.

    Roo

    ReplyDelete