David Dsilo2


Dave Dellenbaugh Sailing

David Dellenbaugh is a champion helmsman, tactician, author, coach, rules expert and seminar leader who has spent his career helping sailors sail faster and smarter.Here are the learning resources that he has created to help you improve your racing skills.


Preparing your boat is a very important part of going fast. Just as a ski racer wouldn't dream of skiing an icy course without sharp edges, today's winners wouldn't dream of entering an important series with a poorly designed boat, a slimy bottom or an inefficient deck layout.

Preparation involves more than simply your boat, however. In order to go fast, you have to be ready in every way possible, including your sails and crew.

The main point to remember is that what you do (or don't do) before you go sailing can have as much impact on boatspeed as what you do while sailing. You can't just jump on your boat, leave the dock and expect to reach your performance potential. If you aren't prepared, chances are good you'll return to the dock feeling like you wasted your time. 

Your Most Important Resource

It's easy to argue that the people on your boat are your most important resource for going fast. Even if you have the best hull design and fastest sail shapes, you are nowhere without a crew that can handle the boat and trim the sails throughout a race. No matter what kind of sailing you do, it's almost always the crew, not the hardware, that makes winning possible.

Unfortunately, finding and keeping good crewmembers can be difficult. The most important crew quality is undoubtedly enthusiasm. A novice sailor with energy and interest has much more potential in the long run than an experienced sailor who is burned out. An eager beaver will be much more willing to practice, make a season's commitment and work as part of a team.         

Once you have a crew, you really need to spend time on the water. "Practice doesn't make perfect," said Vince Lombardi, "perfect practice makes perfect." When you go out practicing, always set a goal. Racing sailors are competitive by nature, and most will learn more from practice if it involves competition.

Practice tips:

      1) Find another boat your size to tune with. Testing boatspeed or sailhandling maneuvers against a competitor will keep everyone interested for a longer time.

      2) Set goals for certain maneuvers and try to improve on them. For example, see how fast you can do a bearaway spinnaker set or a straight-line genoa change.

      3) Let all crewmembers help formulate practice plans. Give compliments when people do something well.

      4) Always take a learning attitude. The goal is to see how much everyone can learn each

      5) Use all your practice time efficiently. No one wants to feel like they're wasting time. Use "down time" to calibrate instruments, take photos of sails, practice person-overboard drills and apply measurement marks on spreaders, tracks, etc.

      6) A good time to practice is the morning of a race. This is an easy time to get the crew together, and it gives you the advantage of sailing the race course early. Don't wear out your crew, however.

Before every race, it's important to make specific crew assignments and then go over each person's responsibilities for each maneuver. Throughout this book, you will find charts of every maneuver and what the crew should be doing. In general, we will talk about a seven-person crew; you will have to modify this according to your crew size and boat layout.

Their general assignments for the standard positions of the crew are as follows:

Helm -- Primary responsibility is to steer the boat fast. Gives commands to help coordinate maneuvers. Continuously tells trimmers about feel of boat. Helps with tactics.

Cockpit #1 -- Mainsheet. Handles mainsheet, traveler and hydraulics.  Usually doubles as navigator and/or tactician.

Cockpit #2 -- Trimmer. Responsible for trimming sheets and adjusting lead positions.  Must keep track of boatspeed and target boatspeed. Talk with helm about steering and trim.

Cockpit #3 -- Grinder. Grind the winches and help with tailing of sheets and guys.

Pitman -- Tails and releases halyards. Handles topping lift, foreguy and other controls led to aft end of cabin house.

Mastman -- Handles all mast functions, including inboard end of pole, jumping halyards, reefing, etc.  Helps foredeck gather and pack sails.

Foredeck -- Handles all foredeck responsibilities: sail changes, pre-start lookout, foot skirting, spinnaker set-up, etc.

Preparing the Hull                

Assuming you already have a boat, you should do everything possible to make the hull stiff, light and light in the ends.  These are the race-winning factors, and they will help under any rating rule. (Be sure that any change you make is done within the parameters of your rating rule.)

Sailboats are fastest when their weight is concentrated in the middle of the boat.  The higher the pitching moment (the more weight there is in the ends), the more the boat tends to bury in one wave and lift high over the next, pitchboling and slowing itself down. Pitching moment also applies to weight in the mast; more weight here means, among other things, more heel.

When you understand how pitching moment is calculated, it's easy to turn into a fanatic about getting rid of weight in the bow, stern or at the top of the mast.  Look at the formula for pitching moment:

      Pitching moment = lbs. x ft.2

Let's say, for example, that you have a 20 lb. masthead fitting on the top of your mast. This fitting is 40 feet away from the boat's center of gyration. Therefore the fitting contributes 20 x (40x40) = 32,000 foot-pounds. For every pound you can remove from that masthead, you will reduce the pitching moment by 1,600 foot-pounds!

The big contributors to a boat's pitching moment are the following:

  • Weight in the mast.
  • Furnishings near the bow or stern of the boat.
  • The rudder and steering gear.
  • The keel (not far from the center of gyration but very heavy)
  • A disorganized, spread-out crew. Obviously you want to center your crew in the middle of the boat as much as possible.
  • Sails when set. These add a lot of weight aloft, especially if they are older, heavier sails.
  • Sails stowed in the ends of the boat. While racing, put sails on the floor in the middle of the boat. (Make sure you comply with rating rule requirements.)

Get into the habit of conducting weight hunts to remove the junk that accumulates during a week or season.  The only thorough weight reduction technique is to empty the boat completely and then provision it with only what is needed for the next race.  Obviously, if you remove weight that was onboard when the boat was measured, you have to re-measure the boat.

Safety Equipment -- The crew's safety is an often-overlooked and obviously very important part of preparing your boat. Not only should you ensure that you have all the safety equipment required for your racing category, but everyone onboard should know where the equipment is and how to use it. In an obvious place down below, post a waterproof page with a list of all the equipment and where it is stowed.

Items like life jackets, safety harnesses, lights and flares should be easily accessible. If it takes five minutes to dig out your life raft, you may as well not carry it. Every time you have someone new onboard, review safety procedures, especially man overboard. Whenever you have a chance, throw a life cushion overboard suddenly and make the crew pick it up as if it were a person in cold water.

Don't forget the seasick pills and other first aid supplies. You'll be surprised at how many people get seasick offshore. To go fast, you definitely need all crewmembers functioning as well as possible, and this can be a significant part of preparation.

Preparing the Rig

Check your mast over regularly for possible failures by sending a crewmember up the rig on a regular basis. Make sure you tape over any pins that might come loose and any places where a sail might tear. With masts, a preventive approach is definitely the smartest (and safest) route!

Weight -- The mast is a notorious contributor to pitching moment; excess weight here is slow.  Besides reducing all-up weight, keep the mast's center of gravity as low as possible.  With an older boat, consider the purchase of a modern racing mast.

Windage -- Windage creates drag by interfering with the air flow just as it strikes the leading edge of the mainsail.  A well-designed mast minimizes the area projected to the closehauled apparent wind.

When the diameter of a mast is reduced, the thickness of its walls must be increased to preserve its overall strength. A small-section, thick-wall spar can be safely bent further than a large-section, thin-wall spar of equal strength. So the small-section spar not only has less drag, it allows more control over the mainsail.

Triple spreader rigs are often used on bigger boats to reduce weight. The spreader tips act as anchors for the bend-inhibiting upper shrouds.  The combination of a triple spreader mast and highly tensioned shrouds produces a spar of considerable strength and rigidity.  However, such a mast is vulnerable to focused loads such as a spinnaker pole rolling into the water on a broach.

Preparing the Bottom                           

As we have said, your keel and rudder are as important as the main and genoa. Just ask the sailors on Australia II who won the America's Cup with a winged keel.

The efficiency of underwater foils depends on their shape and their fairness.  With a J/24, for example, a factory-fresh boat is not competitive until the keel has been faired. Here are some ideas for how to get the most out of your "blades."

Shaping your foils -- Ideally, your keel shape should conform to the 4-digit series of NACA foil sections in Abbott and Von Doenhoff, Theory of Wing Sections (New York, 1949).  To make a set of templates for your keel, follow this procedure:

      STEP 1 -- Measure the chord lengths of your keel at 5% and 50% of its span down from the hull.

      STEP 2 -- Using parallel straight edges, measure the keel thickness for these chords.

      STEP 3 -- Divide thickness by chord to compute the depth of your keel at these points.  For instance, a 3 1/16" thickness and a 34" chord length give a depth of 9%. Note that for a keel and a sail of the same sectional curve, the designated depth of a keel is always twice the depth of a sail.

      STEP 4 -- Refer to Theory of Wing Sections to find the 4-digit shape for your depth.  For a depth of 9%, the 4-digit shape is designated as "NACA 0009". The first two columns of the offset table plot the curve in x and y coordinates as a percent of the chord length.  Convert these percentages to full-size measurements for your keel.

      STEP 5 -- Plot out these points onto a thin, rigid sheet of material such as formica, aircraft plywood or aluminum.  Connect the points with a French curve.  Cut out the template along the line, sand it smooth, and it's ready for use.

      STEP 6 -- Using the same information, construct a leading-edge template for the front 10% of the section.  This template improves your accuracy on the most important part of the foil.

Now that your full set of templates is complete, use them to fair in your keel.  The most important goal is to make your keel symmetrical from side to side. You also want to eliminate concavity in the after end.

Use a given template for chord lengths equal to or shorter than itself.  Snug the leading edge of a too-long template into position, letting the last few percent of the template hang off the trailing edge.

Fill in the hollows with epoxy and then sand, sand and sand some more.  Consult an auto-body instruction manual for the best tips on shaping and sanding; the topic is too lengthy to be included here. 

Some tips:

  • Hold a light at a shallow angle to the surface to make irregularities jump out.
  • Cultivate your sense of touch.  Run a hand over your work, paying close attention to the gentlest of bumps and hollows.
  • If you are working with a friend, check each other's work.  It's impossible to be your own quality control inspector.
  • The cutting speed of sandpaper depends on how convex the surface is. To avoid sanding "flats" into the curvy leading edge, rock the sanding block as you work.  Conversely, gentle high spots on the trailing sections of the foil require much sanding to eliminate.
  • Avoid concavity in the aft sections of your foil.  On centerboards and rudders, concavity causes vibration.  A straight edge should lie flat on the blade without letting any light through.
  • Square off the trailing edge to protect it from chipping. However, if you get vibration in your rudder, you may have to round off one or both of the corners on the trailing edge.

Finishing your bottom and foils -- The key to good painting is good preparation.  If your hull is fair and smooth, the paint job will turn out fine.  The modern two-part epoxy paints don't cover errors, they emphasize them.  So go out of your way to insure that your work is error-free. 

A brushed-on finish must be wet-sanded to reduce its irregularities to within the boundary layer of stagnant water that clings to the hull (see flow discussion below).  Begin with 220 wet paper, folded four times into a pad and held against the heel of the hand or clipped into a neoprene-padded sanding block. 

Sand in a crisscrossing pattern of diagonals, using plenty of water to wash away the grit.  Two drops of detergent per bucket of water help to prevent the paper from clogging.  Change your water and replace your paper frequently -- the job is tedious enough with clean water and sharp paper.

Sand with 220 only until you have taken the gloss off the paint and achieved a uniformly matte finish.  Check your work by squeegeeing the excess water off the hull and viewing it against reflected light.  Once the 220 work is completed, switch to 400, sanding in the direction of the water flow (at 45 degrees to your 220 strokes).  Stop sanding as soon as the 220 scratches disappear. 

The surface is now covered with 400-grit scratches, which are basically "invisible" to water.  Further sanding, buffing and polishing will not reduce skin friction much, but will improve the longevity of some paints by reducing the surface area exposed to corrosion.  Be sure to wipe away the grit with a sponge before it dries, lest it cake on and require resanding.

Understanding Fluid Flow

The two major types of flow over the surface of any foil (e.g. sail or keel) are "attached" and "separated."  Attached flow can be either laminar or turbulent.

Laminar attached flow -- Laminar flow involves smooth layers of fluid streaming over the sail or keel with virtually no mixing between layers.  A marble sinking into a pot of maple syrup experiences exceptionally "clean" laminar flow. 

Under the right circumstances, laminar flow can develop phenomenal lift-to-drag ratios. However, it is easily disturbed, hard to re-establish, and only occurs on perfectly fair (no dumps or hollows) and smooth (no gritty roughness) surfaces.  It occurs more readily at slow speeds, on the leading edge of foils, or in viscous (thick) fluids.  Only a very small part of the flow over any keel or sail will be laminar, and that will happen only part of the time.

Turbulent Attached Flow -- Turbulent flow is a more forgiving type of attached flow.  Normally, laminar flow over the leading edge of a foil changes into turbulent flow for the middle and trailing sections. 

The transition from laminar to turbulent is easy to simulate. Simply turn on a (non-aerated) faucet slightly so that a thin stream of water pours out.  This is laminar flow.  Now, turn up the faucet gradually.  Eventually it will turbulate, breaking into a strong, bubbling stream.  Increasing the velocity of the stream creates turbulent flow.

The goal when finishing your bottom and trimming your sails is to establish attached flow.  The laminar-turbulent distinction, while fun to speculate about, bears no practical significance for racing sailors.  Laminar flow's sensitivity to disturbance makes it a rare and fleeting phenomenon on the sails or keel of a boat crashing through the waves.

Separated flow -- Here is the real villain.  Whenever you have rough spots on your keel, an overtrimmed sail or turn your rudder abruptly, your sail, rudder or keel will stall.  On a stalled foil, flow has separated from the surface and refuses to follow its curve. 

Separation starts at the trailing edge and progresses forward.  Partial separation is neither bad nor uncommon; typically, 10%-20% of your your sail has separated flow when you sail upwind in medium air.  But when the separation point creeps up to the leading edge of your genoa and the leeward telltale begins to dance, the lifting force plummets abruptly. The same thing happens with your keel.

Sometimes, of course, stall is the best you can hope for.  When sailing on a run, for example, your mainsail is working under 100% stall.

The golf ball -- The classic example of laminar, turbulent and separated flows is the golf ball, which has certain similar characteristics to your bottom and keel.  Golf ball dimples are designed to lower drag and increase range.  Here is how.

A perfectly smooth golf ball develops laminar flow along its leading edge.  Air flowing over the forward half of the ball reamins attached and laminar.  But once it rounds the corner and attemps to follow the surface's curve back in, the air runs into trouble.  Since laminar flow is by nature easily destroyed, it separates from the golf ball almost immediately.  The separation point is just behind the widest section of the ball, so the ball drags a wake of eddies as wide as itself through the air. 

The early golfers noticed that their old, chewed-up balls flew farther than brand new, smooth ones.  Evidently, the roughness turbulated flow and reduced, not increased, drag.  Turbulent flow remained attached to the golf ball longer, separating into eddies only after its diameter had narrowed considerably.  Golf balls now come from the factory with the right amount of roughness (dimples) built in.

There implication of this for boats is that your bottom doesn't have to be perfectly smooth.  In fact, a bit of roughness may actually help. The famous "riblets" on Stars & Stripes' bottom are a great example of a non-smooth surface that maintains laminar flow longer and thereby reduces drag.


Obtaining accurate and reliable information from your instruments requires that you spend some preparation time ensuring that your sensors are installed and functioning properly. This is a lengthy subject, so we will discuss only your two most important instruments: the boatspeed sensor on your bottom and the apparent wind sensor atop your mast.

Boatspeed -- The location of the sensor is critical.  It should be located close to the centerline of the boat.  More important however, is the fore-and-aft placement.  If the sensor is too close to the keel, increased lateral flow of water when the boat is heeled over changes the sensor's readings. If the sensor is too far forward, it is affected by wave action, and may even come out of the water when the boat goes over waves.  These obviously will produce erroneous results.

If the boatspeed sensor is put back in the boat differently after the boat has been out of the water, the sensor will read different values.  The alignment and depth of the sensor should be marked to duplicate the previous installation.  This is important for consistency in results.             

Apparent wind -- The sensor for apparent wind at the top of your mast is affected by many factors: upwash from the sails, leeway, heel, and symmetry of the wind vanes, mounting bracket and masthead crane. Obviously, if the vanes are bent or the mounting bracket is loose, there will be inconsistencies in your readout.

Having an out-of-line backstay crane has a subtle but even more dramatic consequence. As backstay tension increases, the top of the mast twists, along with the masthead unit. Wind angle readings will be different on each tack. Another thing to watch out for is bent anemometer cups, which will reduce your apparent wind velocity readings.

The Coding Connection

One of the most important preparation jobs you'll have to do is to code all your sail trim adjustments. This is key to learning fast settings and being able to duplicate them.  Before setting out onto the racecourse, be sure that you have added number scales to all tracks, halyards, etc. This is essential if the boat is to go faster and improve as the season progresses. Here are some priorities:

Genoa lead angle -- Knowing this angle will be important when we get into genoa trimming. Figure 21 shows a method of constructing a small triangle on the foredeck and then extending its hypotenuse aft to arrive at the lead angle for an existing (or future) genoa track.

Rudder angle -- The angle that your rudder makes with the centerline of the boat is your best measure of windward helm.  When your boat is out of the water, mark your helm at the 0 degree, 2 degrees, 4 degrees and 6 degrees positions to port and starboard. Use tape bands on a wheel or scribed lines on the deck or rudder post for a tiller. To find the calibration points, follow this procedure:

      STEP 1 -- Measure the distance from the rudder post to the trailing edge.  This length is w.

      STEP 2 -- Multiple w by the sine values for each angle to arrive at r, the distances that you will have to swing the trailing edge off centerline.

      STEP 3 -- While your partner moves the rudder to each position, put the appropriate marks on your wheel or tiller. Remember that any play in the rudder head means the rudder will not turn as far as the wheel or tiller. Your best bet is to eliminate play.

Spreader references -- Put bands of tape (reflective tape is best if you sail at night) around your upper spreaders at 3 inches, 6 inches and 12 inches in from the spreader tip. These bands will serve as a stationary reference point to help judge how close the genoa is trimmed to the spreader.

Halyard tension -- Mark your genoa halyard at maximum hoist so you won't raise the halyard too high, and so you'll have a halyard tension reference. Mark the halyard so your mark is at the black band when it is two-blocked. Place a scale on the mast alongside the genoa halyard with the zero point at max hoist. If you have wing halyards, mark them where their shackle is even with your centerline halyard. This way you can use the same genoa halyard numbers with any halyard.

Preparing Your Sails

One final area that needs attention before you start a race are your sails. Sail construction and cloth have been improved greatly over the past decade, but sails still need a lot of TLC in order to insure that they will perform optimally for a long time.

Sail preparation begins at the end of your last race. Make sure that you rinse off salty sails with fresh water and dry them before folding. The last thing you want is to reach the starting line and realize that your 3/4-ounce chute is still wet from that overnight race three weeks ago.

Genoa care -- It's absolutely essential that you put spreader patches on every genoa before you go sailing with it. A genoa without spreader patches is an accident waiting to happen. One other caution about genoas: Do not exceed the sailmaker's recommended wind maximum. If you do, you'll either have a balloon or shreds.

Label the sail bags and clews -- Make sure all your sail bags are marked clear enough on the outside so a bleary-eyed mastman can find them when doing a sail change at 2 in the morning. On the clew of every sail should be written the following: Sail ID, maximum wind for sail, lead position. You can also add other numbers such as halyard tension and distance off spreader.

Pack and flake sails -- Before you get to the race area, be sure that all your headsails and spinnakers are packed neatly in their bags, ready to be used at any moment. All sails should have head, clew and tack readily accessible. Heavy-air spinnakers should be stopped with rubber bands or yarn.

Telltale placement -- Put telltales in the following places -- front of jib (about a foot back from the luff); leech of main (usually on the batten ends); and on the shrouds, backstay, topping lift, etc. Yarn is the best and attaches to sails well with sticky back tape. For jib telltales, use red on port and green on starboard, with one side always higher than the other. This makes it easier for the helmsman to figure out which telltale is on which side.

Preparing for the Race

Most of the preparation we've talked about so far covers things you can (and should) do long before the big race day arrives. There will also, however, be some things that you'll have to do that morning. First of all, read the North U. Smart Course book for ideas on collecting data, planning strategy, etc. Before leaving the dock, center all weight by emptying the bow and stern areas of sails, personal gear and other miscellaneous items.  Leave the dock in time to arrive at the starting area one hour before the start so you can do the following:

  1. Organize the crew and assign positions.  Discuss or practice every boathandling maneuver.
  2. Select the headstay groove that will make the first headsail change an inside set.
  3. Pump bilge (water weighs 8 pounds per gallon!)
  4. Center propeller.  In light air, band the propeller to keep the blades from opening when drifting.
  5. Back down to get rid of seaweed.
  6. Pre-set spinnaker pole with guy in place, foreguy attached, topping lift attached and taped to mast.
  7. Pack all spinnakers. Make sure most probable sails are accessible.
  8. Have navigator post course in cockpit.  Sail each course for a short time and record the apparent wind angles expected on each leg.
  9. Sail on each tack and choose target speeds.
  10. Go fast.

Boat Preparation -- Preventive Maintenance

Breakdowns are neither safe nor fast. While broken spars and blown-out sails once were the marks of a hard-pushing clipper ship captain, today's racing sailors do everything possible to minimize gear failure.

Regularly inspect all the standing and running rigging, steering gear, sails, fittings and electronics before every race that you intend to win.  Tape every exposed sharp edge and cotterpin. Stock your onboard tool kit with the following items (lightly coated with oil to prevent rust):

      Screwdriver set - phillips and standard

      Knife (should always be available on deck)

      Socket set

      12" Crescent wrench

      6" Crescent wrench

      Vise grips

      Slip joint pliers

      Allen wrenches

      Hacksaw and extra blades

      Nico press tool with sleeves & thimbles

      Crosscut file

      Needlenose pliers


      Spray lubricant

      Channel lock pliers

      Tape measure

      Bolt cutters

      Duct and electric tape

      Assortment of shackles, pins, stainless nuts and bolts, spare line

      Parts for winches, engine, instruments, steering system

Sail Repair Kit:

      3 yards of adhesive-backed 2-ounce Dacron

      Sticky-backed rip-stop nylon


      Seizing wire

      Assorted needles and thread

      Yard of 1" webbing

      Hot knife

      Slides, hanks (that will fit your spars!)

      Slot pre-feeder