The State of DN Racing

by Jane Pegel - US805 - April 1986

I'm pleased to make public the fact that I'm completing my 31st season of DN racing. My first DN was #305. This number still remains in the family and is registered to my husband Bob. I race under DN 805 and my daughter, Susie, races under DN 905. I have a record of all official class publications dating back to 1956, and I'm the only person whose name appears in the race results of that vintage who is still racing DNs. With any luck I'll be racing hard for a good many more years, in fact Bob is going to build me a new hull.

The point is I've seen a lot of sailors and boats come and go. The Class has weathered good seasons and bad and experienced some growing pains. The 1986 North Americans was not the largest ever held, but I think the level of racing was perhaps the best we've had. Seldom have we seen the Champion come away without winning a race. What does this mean? I think it indicates that a lot of sailors have learned how to set up their rigs, align and sharpen their runners, and sharpen their sailing skills to a level required by the world's most competitive iceboat racing class.

Through the ingenuity of its sailors, most of whom build their own boats, the DN has evolved into a boat that is faster, lighter, stronger, easier to sail, and more fun to sail than it was when I started in the Class. Original DNs hiked a lot, were heavy to carry, and broke down. These factors made them hard to sail. In fact, I bet that I'd be hard pressed to physically handle one of those boats and race it hard all day. I'm thankful the rules for the Class have enabled it to become such a fine boat to sail and that these rules have encouraged innovative sailors to join the class, for they're fun to race against.

Ultimately, I guess it's the people in the DN Class that have made it so much fun. Sure, we sometimes have disagreements concerning the proper approach to governing the Class, but we are unanimous that DN racing is a "high".


As with sailboat racing, one of the things that makes iceboat racing so satisfying is the "honor Code" that is required on the race course in order to make the game a fair one. The officials do not blow a whistle, stop the action, deal out a penalty, and award a bonus tack to the fouled boat. The sailors police themselves, give way to the right-of-way boat, and when an honest error in Judgement is made, Justice is served through the protest procedure.

To the credit of the racers at the North Americans, there were no serious collisions. But there were a number of fouls. A few of these were carefully resolved by the protest committee, and one sailor voluntarily acknowledged his error and withdrew from a race. In these few instances the game was fairly played. Unfortunately, these instances were outnumbered by foul situations that were not fairly resolved. In conversations following the racing, many of the sailors expressed the opinion that not everyone is fully aware of his responsibility in various close quarter racing situations. I have been asked to explain the proper application of the rules and the appropriate boat handling for a couple of the most common situations:


"When two yachts are sailing on-the-wind, the yacht on the port tack shall keep clear" of the yacht on the STARBOARD TACK. "When two yachts are sailing OFF-THE-WIND, the yacht on the PORT TACK shall keep clear of the yacht on the STARBOARD TACK." When boats to which the above rule applies are converging, it is the responsibility of the boat on the port tack to give way to the boat on the starboard tack. However, BOTH BOATS are obligated to prevent a collision, so if the starboard tack boat believes that the port tack boat is not going to give way, then the starboard tack boat is entitled, indeed is obligated, to take evasive action.

In a port-starboard situation, the proper steps to comply with the rules are as follows.

  1. The port tack boat should let the starboard tack boat know she sees her. The helmsman of the port tack boat should markedly turn his head toward the starboard tack boat, signal with his hand or perhaps by nodding his head, so the starboard tack boat is assured the port tacker sees her.
  2. The port tack boat should alter her course (tack, jibe, bear away, or freshen, as is appropriate) A COMFORTABLE DISTANCE FROM THE STARBOARD TACK BOAT.
  3. If the port tack boat does not take evasive action, then the starboard tack boat should tack, jibe, bear away, or freshen, as is appropriate. Because evasive action taken by the starboard tack boat is usually at the last possible moment, she should maneuver in a direction that will reduce the closing speeds of the two boats so if a collision does occur at least damage will be minimal. For example: Port and starboard boats sailing on-the-wind are converging. Only these two boats are in the area. The port tack boat takes no evasive action. The starboard tack skipper estimates he'll hit the port tack boat at the mast. The starboard tack boat should head up, ease sail, and even may tack. This action will slow the starboard boat and put her motion more parallel with the port tacker. If the starboard boat bears away to go behind the port tacker, the chances of a harder, and perhaps head-on collision are more likely.

NOTE, this evasive action of the starboard tack boat is not a Violation of the rule: "a right-of-way yacht shall not alter her course so as to mislead or prevent a non-right-of-way yacht from keeping clear." In the above example, the non-right-of-way yacht had not taken any "evasive action" and Fair Sailing requiring common sense, safety and good sportsmanship required the starboard tack boat to alter course. If the port tack boat had begun to lay off to go behind the starboard tack boat, and then the starboard tack boat had altered course so the port tack boat could not avoid her, the burden would be on the starboard tack boat. THIS SELDOM OCCURS.


The primary difference between sailboat rules and iceboat rules is in those that apply when sailing off-the-wind and when rounding the leeward mark. The iceboat rules are designed to make it as safe as possible to get around the leeward mark without running into another boat.

The highest speeds are attained when sailing off-the-wind. The most difficult maneuver in racing is making a good turn at the leeward mark. The convergence of multiple boats complicates the maneuver. The rules are designed so the same boat has right-of-way while rounding the mark that had the right-of-way all the way down the leg. Think about it this way:

  1. Marks are rounded to port.
  2. Boats are on the port tack as they round the mark.
  3. As the boats make their approach to the mark and are close enough to each other so that there might be a collision, the rules provide the boat that is inside of the other has right-of-way, even 100 yards from the mark. For example:

    a)  If two boats are side-by-side and on port tack sailing off-the-wind, the windward boat has right-of-way. Because the windward boat already has right-of-way, there is no transfer of responsibilities as the two boats get closer to the mark, the windward boat is inside, and must be given room to round the mark.

    b)  If two boats are approaching the leeward mark on opposite tacks, the starboard tack boat has right-of-way. The port tack boat must bear off to leeward to honor the starboard boat. In bearing off, the port tacker automatically gives the starboard boat room to jibe inside and to windward of the port tacker, which then puts them in the same relative position as the two boats in example 3a. Of course, the starboard tacker has the option of actually forcing the port tacker to jibe onto starboard tack too.

The danger of a collision, and a foul, exists when boats are side-by-side (as in 3-A) or aiming at each other (as in 3-B). A collision may also exist when a faster moving boat approaches from the rear. Whether approaching a mark, or out in the middle of the course, a boat coming up from behind cannot run into the boat ahead. If the boat ahead is moving at the same speed, the chasing boat can't catch her to hit her, so there isn't a problem. In the final approach to the mark, the faster moving boat approaching from the rear must not pull alongside on the inside if the boat that was ahead has started her rounding maneuver.

EVERYONE MUST CONSIDER THE POINT WHERE THE ROUNDING MANEUVER BEGINS IS INFLUENCED BY THE WIND AND ICE AND ALL OTHER BOATS IN THE AREA. Because the speeds of the boater involved may be very much different (one guy might be pushing, another guy in a screaming hike), common sense and safety ARE SUPREME. There is not a specified number of boat lengths, as in sailboat racing, to tell us where the rounding maneuver begins.

Quick and Dirty Ice Claws

ice_claws.gif16.58 KB
by Bob Dill
September 1989 (Revised January 1991)

Most people who iceboat for a number of years find themselves in the water sooner or later. If you ever find yourself in the drink one thing you will really WANT to have is a pair of Ice Claws. They are also called Bear claws, ice awe, ice picks and other things. Being able to get out quickly is key to surviving immersion in 32 degree water.

Ice Claws make getting out a very easy. Many of the people who die on ice do so because they don't have ice claws and can't figure out how to get out without them. Getting out without ice claws is possible if you know how, but it is much less reliable (see Self Rescue Technique). Anyone who is on the ice should ALWAYS have a pair of ice claws with them.

In Vermont we have had two problems with them. First, they tend to reside in tool boxes rather than with sailors. We have had more than one solo sailor go for a swim with their ice claws launch site. So far they have been able to extricate themselves.

The other problem we used to have is that many sailors didn't take the little time it takes to make themselves a pair. To address that we mass produced about 50 pair of crude ones. These have been given to everybody and anybody. No one seems to object to their rough finish when they are given a pair.

The basic materials are 3/4" by 1 " hardwood strips, 20 penny common nails, Velcro and 3/16"" nylon rope. The drawing shows one of many designs and a minimum investment construction method. Make a lot of them. A batch of 50 won't last very long if you are reasonably diligent about giving them away. One person can make about 10 in an hour of working time.

Once you have made plenty of them, give a pair to everyone you know who spends time on the ice. A brief account of the difficulty of getting out without them will help assure that they don't get left at home. Put a couple in your pockets and a few more in your tool box to give to people on the ice. Sooner or later you will save somebody's life.

There are several styles and ways of making them. The method shown and described here is for making a bunch with a minimum investment of time and money.

  • Prepare the nails by cutting them off with a bolt cutter (or hack saw). The length from the pointed end should be 7/16" shorter than the amount your 13/64 drill sticks out from your" drill chuck. Make a nail nipper gauge by drilling a hole(s) in a board the right depth to bolt cut the nails to the correct length. 20 penny common nails were chosen because they are plenty strong enough but they are much easier to cut than cement nails.
  • Velcro: Velcro Hook is glued to the bodies. Use 2" wide hook. if you can get it, use #800 (or" equivalent). It has 0.008" monofilament in the hook and is stronger than #650. your sail" maker may be a good source. Store the hook tape flat and unwrinkled. It will be much easier to glue on that way. Cut it into 1 1/2" lengths to be glued across the bodies before they are cut" apart.
  • Use 1" wide pile (loop) tape to hold the halves together. cut it into about 5" lengths.
  • Note for step 6: The 13/64" hole for the nail should be about 7/16" longer than the nail. Assemble one pair far enough to check that the hole depth and nail length are proper.
  • Note for step 7: Putting a flat weight on the VELCRO hook will hold it down while the epoxy cures. This may not be necessary if you have kept it flat and wrinkle free.
  • Note For Step 11: Wet the hole and nail with epoxy before pushing the nail in. You often have to push the nail fairly hard to get it all they way in because of excess epoxy in the hole.
  • Note for step 13: Prepare lanyards by cutting the nylon rope into 48" lengths and fusing the" ends. Both ends of the lanyard are pushed in from the side opposite from the VELCRO. An overhand stop knot keeps them in.

The safest way to wear them is to put the lanyard over your head and under one arm. The lanyard is designed to be short enough so they won't flop around. It's length can be adjusted with a slip knot stopper knot.

If you have questions or suggestions give me a call.

Quick Ice Claws drawing

Self Rescue Technique

by Bob Dill

Occasionally people find themselves in the water with wet, slippery black ice all around them. We had a near fatality in Vermont a few years ago when a skater tried to cross a pressure ridge. He stepped on a small loose plate and fell in. He had no ice picks and was unable to get out. His cries for help were heard by nearby iceboaters after he had been in the water for about 10 minutes. He was fairly hypothermic by the time we got him to shore.

To assess what is required to get out in this situation, we cut a hole in the ice and jumped in with rope and a dry suit on. By far the easiest way to get out is with ice picks, ice awls, bear claws or whatever you call them. If you don't have them, don't panic and act fast. Swim to the edge of the good ice, put your forearms on the ice, get your body near horizontal and with powerful frog kicks you can push yourself out. You should lift with your arms, but only straight up. This will help you get over the ice edge as you kick. Don't try to pull yourself out with your arms, they will only slip off. The idea is to keep yourself low and use the frog kick to push yourself onto the ice. Once out, get to shore or help quickly and out of your wet clothing as soon as possible.

A warm shower is almost always in order after a 32 degree swim. If a victim is having difficulty walking, talking or has a noticeable pallor or weak pulse in his extremities, call a rescue squad. Try to rewarm the victim in a shower or bath or at least with other people and warm drinks until the rescue squad arrives. Concentrate on warming the torso, not the extremities. The rescue squad should be called as soon as things even begin to look like significant hypothermia might be involved so they can be ready and waiting when the victim gets to shore.

I often wear a thin farmer John wet suit when sailing on questionable or unknown ice. They are comfortable, give good back padding for bumpy ice sailing and make being in the water much less dangerous and uncomfortable. The wet suit will also make getting to shore much less urgent. If you get wet a long distance off shore, this could be a crucial consideration.

Ice Grain Structure

by Bob Dill - March 1990 - Revised January 1991

How ice forms in the Fall has a lot to do with how it behaves in an advanced thaw condition in the Spring. The following article reviews how water ice forms into one of two types of ice that are very different from each other.

There are two basic types of ice: water ice and snow ice. Water ice is ice that forms under the surface of the ice sheet by water solidifying into the crystal structure of the bottom of the ice sheet. It has a grain structure that is uniform through the ice thickness. It contains relatively little dissolved air.

Snow ice is any ice that forms from snow or slush freezing on the top surface. It has a grain structure comprised of the ice granules from the original slush. It contains a lot of air trapped between the ice gains.

This article primarily concerns water ice. In most cases the snow ice will melt off the underlying water ice after an extended thaw because it strongly absorbs sunlight.

Melting Factors

Ice melts in two ways, on the surface and internally. Surface melting is caused by warm air, especially with wind and to a lesser extent, rain. In December 1990 we had 4" plate of ice on a" pond near Burlington. 24 hours of 47-50 degree temperatures, 15-30 mph wind and less than an inch of rain melted 2 inches of the 4" plate and completely melted 2 + inches of ice on several" warm water holes. In Syracuse, Indiana at about the same time, they had similar ice exposed to the same temperatures with 4 inches of rain. They had very little ice loss.

Puddles of water on the ice, whether from warm wind or rain. They drain through any crack or hole in the ice. The water erodes little holes into a runner sized one. There are some excellent pictures of this in Think Ice. The size of the holes is dependent on how much water drains through them and how warm the water is. They can form to runner size in less than 24 hours in 12 inch thick ice. This often happens in mid-season thaws.

Internal melting of thick ice is usually a more gradual process, requiring several days of sunny, above freezing days and warm nights. Of course, if the ice is only a few inches thick and it is 50+ degrees and sunny, things can happen fast!

Ice Grain Types

Water ice freezes into crystal families called grains. The melting takes place between the grain boundaries of the ice. The melting point of water is slightly lower at the grain boundary because the crystal structure is less perfect there.

This first shows up in black ice as sheets and strings of bubbles in the ice along the grain boundaries. The ice becomes gray from the bubbles after a while. After an extended period of heating by the sun the grain boundaries will melt all the way to the bottom of the ice, forming many tiny drain holes. This is evident when all the puddles disappear from the ice surface of thawing ice.

When water ice is exposed to prolonged sun at above freezing temperatures it thaws into either honeycombed ice or, if the ice grains are larger, into interlocked grains. In the latter stages of the thawing process there is a big difference in the weight bearing ability of these two grain structures.

Well over a foot of honeycombed ice may not support a man or a DN. A piece of large grain ice only three inches thick with the same thaw history will support a man. It can sag as much as 6 inches before breaking.

The grain structure of the ice is determined by the conditions of the ice when it freezes. When ice freezes an ice crystal starts growing at a nucleation site on the surface.

Large Grain Ice

A nucleation site is something the cold water molecules will accept as a seed crystal. It can be a small ice crystal, a snow flake, or a piece of dirt the water accepts for an ice crystal. If the surface freezes in still conditions with no snow falling. relatively few nucleation sites are available. The ice crystals will form long, flat spears (they are dendrites, look like Christmas trees and can be seen in any still water in the process of freezing). The spears grow until they run into one another. They then fill in the intervening surface with dentritic branches.

If it is not disturbed, the first thin skin of ice determines the grain structure for the ice that forms as the sheet thickens. Some of the spears grow rotated in the water surface. The ice grains that develop from the rotated spears will grow at an angle the surface. The grains mechanically lock together because the grain boundaries are relatively large planes which have a lot of interlocking between the grains.

Small Grain Ice

Small Grain ice (Honeycomb ice) starts with a lot more nucleation sites. They can be snow or frazzle. Even a very light snow provides plenty of nucleation sites to form a small grain structure. If you look closely at ice forming in still conditions with a little snow falling on its surface, you can see the small grain structure developing. Frazzle is broken ice spear slush that forms in water disturbed by waves. In cold, wavy conditions frazzle can form a thick slush on the surface.

The ice that forms with a lot of nucleation sites has grain boundaries typically less than an inch apart. In this case the grains constrain each other so much they grow almost Straight down. This results in the long narrow grain structure typical of honeycombed ice. The relative weakness of small grain ice is a result of the grain boundaries being interlocked on a much smaller scale. This small scale interlocking melts out quickly when the ice melts.

Ice forming on still water with no snow falling will have the largest grain size. As the water is more disturbed the grain size will become smaller. If even a very light snow is falling, small grain ice is almost certain.

Safety on Thawed Ice

If you find yourself walking across well thawed spring ice, looking at the surface of the ice may tell you which ice is strongest. Using a probe (ice chisel or the like) to test the ice before you walk on it is always a good idea on weak or unknown ice.

Small Grain ice is typically dark with a small grain structure made up mostly of 3 to 6 sided polygons. The average dimension of these polygons is generally less than 1 1/4 inches. It chips out into small columnar pieces then hit with the probe. It may be possible to drive the probe through a foot or more if this ice. If the ice feels like it is settling a little when you walk on it, it is!. If you stomp on it you can sometime punch a hole through it. A good time for a dry suit and a belay rope.

A Large Grain Ice surface distinctly shows a much larger and more irregular grain structure. The typical grain dimensions range from 3 inches to as much as 2 feet. This ice tends to have a grayer color in advanced thaw condition. It chips into chunks when poked hard. In an advanced thaw condition, it is much stronger than small grain ice.

It is common to have areas of different grain types mixed together. The size of the sheets of one ice type vary from entire lakes or bays to a patchwork of mixed pieces a few feet in size. Broken up plates of one type often fill in with the other type.

Cobblestone Ice

When a thick ice is thawed enough to melt the grain boundaries all the way through the sheet, an unusual and very rough ice surface can result. The ice melts more at the grain boundaries than on the grains between the boundaries, After refreezing, this can result in a regular but very rough, polished surface. The dimension of the roughness is proportional to the grain size. In large grain ice the result is much like a cobble stone surface. This probably accounted for the extremely rough conditions at World Championship in Arsunda Sweden last year.