Photo: Max Ranchi
[www.maxranchi.com]

Handicap
Rating
Systems
for
Sailboat
Racing

"There is no second ma'am", was the alleged reply. Only partly true, while the other sailboats of equal tonnage had either collided, were dsq's or had suffered grounding's, there was a second, eight minutes later the 47 ton cutter Aurora crossed the finish line. If the race had been run under any form of rating based on tonnage and length, Aurora would have won.

Unlike aerodynamics that set a maximum speed for a 'subsonic' airplane (regardless of its fuselage length), hydrodynamics for a displacement boat sets a maximum speed based on the waterline length of the immersed hull, given equal skill of skipper and crew, a boat with the longer waterline can sail faster.

Visualize a displacement boat, anchored with water flowing past it - a bow wave [termed the 'captive' wave] is created, with lesser waves forming along the waterline. Increase the speed of the water until there is only a 'trough' between the captive and stern wave, the boat will have reached its maximum 'hull' speed.

The longer the waterline length, the more room for lesser wave formation before the 'trough' forms, but once a trough has formed, and if the water flow is increased, the anchor has to drag/break, or the boat's foredeck would be pulled out,
just as a subsonic airplane cannot break the sound barrier, a displacement hull cannot break its captive wave's trough.

In 1854, four years after the schooner America won the Guinea Cup, the Thames Measurement Rule came into being: Tons = ([L-B] x B x .5B)/94. (L = length stempost to sternpost and B = maximum beam). But the rule, based on the wave barrier hydrodynamics, was easy to subvert, move the rudder forward [it hinged on the stern post], it doesn't change the actual waterline length but reduces it in the formulae, and gives the boat an enormous undeserved advantage in a lower 'handicap'.

The lines of the top boat (on right), with a lwl of 64 feet, would have a potential maximum speed of 11.2 knots (square root of 64 = 8 x 1.4* = 11.2 knots).

Compared to the lower boat which also has a LWL of 64 feet, but under the Thames Measurement Rule with its stern post to stem measurement of 54.75 feet, would be rated as if its hull speed could not exceed 10.36 knots (square root of 54.75 = 7.4 x 1.4* = 10.36 knots).

* This 1.4 factor can vary on displacement hulls from between 1.1 and 1.45.

The lower boat, with its 'overhanging stern' would also gain in a decrease in the water friction area / displacement, plus by better concentration of its 'mass' about its center of gravity, better maneuverability.

All 'fat' hulls push against a captive bow wave, making it increasingly difficult to increase speed through the water as they will be pushing against this wave - until it eventually with a trough formed behind it, it insurmountable.

The 1930's ocean liner Queen Mary, now docked at Long Beach, CA., with a LWL of 1,000 feet with her steam turbines had a maximum speed of 30.5 knots. At this speed she had two self-generated waves along her waterline length (square root of 1,000 = 31.624 x 0.96 = 30.5 knots), so she only had to contend with speed reducing 'water friction', as her steam turbines couldn't propel her faster enough to reach the critical 'speed/length' ratio, in the most general layman's terms, the Queen Mary could reach at best a water mach of 0.69

But just as an airplane can be built to break the sound barrier and fly supersonic, with todays hight tech lightweight materials, boats can now be designed to break the water barrier. The 112 ft catamaran Club Med in 2001, sailed 655 miles in 24 hours - 27.29 knots an hour, say mach 1.78 in respect of its waterline length.

The 141 ft mono-hull Mari-Cha IV on her maiden voyage across the Atlantic in 2003, sailed 525.7 nautical miles in 24 hours, 21.95 knots [mach 1.27]. She also set a new mono-hull record of 6 days, 17 hours, 52 minutes and 39 seconds, beating by more than two days the record which had stood for one hundred years by the yacht Atlantic in the 1903 Kaiser's Cup.

The Atlantic built in 1903 was 45 ft longer overall, but only 6 ft longer at the waterline (where it counts), below the waterline she had a long lead keel ending at her rudder, her best 24-hour run was 341 miles [mach 0.84] in the Kaiser's Cup.

A 'Meter Yacht Rule' was developed in 1907 for 6, 8, 10, 12 and 14 Meter Yachts then racing. A 12 Meter is shown at left against a 90 ft J Boat (the America's Cup boat of the 30's), which has similar underwater lines.

There is the the immediate observation, that as windspeed increases with height, part of the J Boat's sail area will be in a higher and stronger 'wind strength'. While difference in square footage of sail area can be be allowed for, there is this problem that part of the J Boat sail area will be in a greater wind strength.

Even if this area of the J's sail area could be 'rated' in some future computer Velocity Prediction Program, the difference in waterline length makes it impossible to handicap such different waterline's, to race equally against each other on a fair and equitable basis so that 'the skill of skipper and crew is the deciding factor in winning/losing'.

For example, a 12 Meter sailing against a J Boat, if the 12 Meter hit the starting line on the 'gun' and the 90 footer was say 10 seconds late, it would be able to power past the smaller at will leaving it in 'dirty' air, and this could be repeated to correct any other lapse of 'sailing skill' by the skipper and crew of the larger boat during the race.

To a lesser extent, this is also true for a 12 Meter sailing against another Meter Class boat with a shorter waterline, such as a 6, 8 or 10 Meter.

In 1928 the Bermuda Rule was created, while previous rules were more for inshore racing, the Bermuda Rule attempted to eliminate unsafe design developments for the purpose of a better rating. Eventually the Cruising Club of America Rule (CCA) resulted with length as the basis with adjustments for beam, draft, displacement and sail area, with factors for stability and propeller.

The Royal Ocean Racing Club, The other side of the 'pond' developed their own RORC Rule for Offshore Yachts, while it had the same intent (to eliminate unsafe design for offshore racing), the Brits were more for Sloop and Cutter rigs than the Yawl rig favored on the American side.

When ocean racing resumed after the World War 2 the rules tended to diverge, in that the Cruising Club of America (CCA) Rule was adapted from time to time to encourage owners to build the sort of dual-purpose cruiser/racer that the club thought desirable. The Royal Ocean Racing Club (RORC) was less restrictive towards the development of the pure racing boat, such as Myth of Malham. By 1961 it was clear that there were two very different rules, the RORC Rule for Europe and the Antipodes and the CCA Rule for North and South America.

November 1969 the Offshore Rules Co-ordinating Committee held its final meeting and a new Offshore Rating Council (ORC) was born. From the ORC, came the International Offshore Rule (IOR): 'with the spirit and intent to promote the racing of seaworthy offshore racing yachts of various designs, types and construction on a fair and equitable basis'.

At the beginning, it did result in 'seaworthy offshore yacht designs', the rule was based upon the CCA approach to sail measurement and the RORC method of hull measurement, for full story go to [ ORC Page ] then on menu at left side, click on IMS Aims & History.

The IOR arrived just in time to catch the boom in international racing represented by the growth of the Admiral's Cup, the Southern Cross and the Onion Patch series. The boom itself caused serious problems in rule management in the mid-seventies. Intense international competition and use of a new design tool, the computer, allowed designers to exploit the Rule 'with odd bulges to the hull to exploit girth and other measurements.

While there is justifiable nostalgia today for the old IOR level rating of the IOR 1/4 ton. 1/2 ton and 1 ton class, change was necessary, as the IOR could and did result in some unseaworthy boats being designed and built. By 1990, the ORC developed the International Measurement System (IMS), structured to rate boats to tenths of a second per mile for the Grand Prix Race boat. The rating takes into account course and wind strength with a Velocity Prediction Program (VPP). For the weekend regatta Racer/Cruiser, IMS Club (Americap 11 in US), permitted use of a simplified rating.

The ratings in IMS, are based only on measurements. There are no debatable subjective components. The relaxed accuracy permits use of sistership measurement data from an extensive database. Unfortunately, what one computer program can measure, another program can find a way around. This has resulted in problems for IMS, allegedly boats that are 'slow and tippy'.

Norman Davant, the Big Boat Series Regatta Developer for St. Francis Yacht Club stated in late 2003: "For the past two years we've worked with US Sailing to handicap boats using Americap II (the US adaption of IMS Club), but it's now obvious that system simply does not work in the tidal conditions of the San Francisco Bay. Because Americap II has been so disappointing, we're encouraging US Sailing to embrace the British IRC as the handicap system of choice, which would be consistent with what's happening in the rest of the world". Davant also says that he has talked with other clubs about using IRC for their major events in 2004, and is reported to be encouraged by the response he's received.

The three handicapping systems most widely used in the US today, are: PHRF (Performance Handicap Racing Fleet) pronounced 'perf'. In PHRF, a boat is assigned a rating in seconds per mile based on the number of seconds per mile the boat is supposedly slower than a theoretical boat which rates 0. Boats usually rate in a range of between 50 - 250. PHRF supplies a single correction factor that is applied regardless of the conditions of the race, and the numbers are assigned locally to reflect actual winning performance of boat, skipper/crew sailing in local conditions. Both time-on-distance and time-on-time handicapping is used under PHRF, the largest handicap fleet in the US - [click for Rule ]. For small centerboard boats there is 'Portsmouth', based on the The Thistle dinghy.

On the other side of the pond, The Royal Ocean Racing Club (RORC) had been pushing their IRC (IRChannel), a rebirth of the old RORC Channel Handicap System (CHS) for club racing in the British Isles. In March 2004, ISAF announced their approval of this RORC rule for use worldwide, by stating that the 'IR' would in future stand for International RuleClub (IRC).

But there might be wrinkles to be ironed out with the IRC, as Don Finkle, RCR Yachts' Performance Newsletter #45, December 11 [http://www.rcryachts.com/newsform.htm], points out in connection with Beneteau Yachts of France: "In the US most of our racing takes place under PHRF, and there are no specific penalties for construction or equipment (with a few exceptions such as the propeller). Therefore, to be attractive to US buyers, they will have to offer boats with rod rigging, tapered masts, more spreaders, and so forth. For European buyers racing under IRC, they need to have clunky rigs with cable shrouds. Fortunately for us, Beneteau will do this on their larger boats, and the 44.7 for example is available both ways. It was precisely this kind of nonsense that drove many of us to one design in the first place!".

With the decline of interest in racing going down each year, it has been commented that this jostling for International position is on par with arguing on the placement of deck chairs on the RMS Titanic. Sailboat Racing globally is highly fragmented and lack of a unified Rule, is presenting a significant problem to organizer's of international events. The principle reason for this situation is the lack of international agreement on a mutually acceptable handicapping system with, for example, the UK committed to racing under IRC/IRM (IRM is the RORC Developement Rule), in Europe and Australia there is IRC, IRM amd IMS.

To address this problem, a new working party was set up (November 2002), sponsored by RORC, ORC and US Sailing to examine whether or not a new 'developement' rule could improve global unity for the Grand Prix big boat racing circuit, and if so, what type of rule would it be? They had their first meeting on 24-25 March, 2003 in Annapolis, MD. This grand prix working party is chaired by Jean-Louis Fabry of France with members Peter Reichelsdorfer and Stan Honey representing US Sailing, David Lyons (Australia) and Stuart Quarrie for the RORC and Paulo Massarini (Italy) and Manolo Ruiz de Elvira (Spain) for the ORC. Olin Stephens is an advising member. Additionally, each of the three partner organizations can provide a technical consultant. Jim Teeters is the consultant for the US Sailing contingent.

At the 2003 Barcelona meeting of the Offshore Racing Congress (ORC), previously Offshore Racing Council, it was reported that good progress had been obtained in partnership with RORC and US Sailing in developing a Grand Prix Circuit Rule for the future.

Indications are, that it will be a 'box rule', and box rule's will be covered in Part 2 of this article.

For a Grand Prix Circuit Yacht, raced under a development rule, the design and building cost would be around $1 million, very substantial for an individual owner, who then has the cost of campaigning on the grand prix circuit. However it is estimated that world wide there are some 80+ individuals who are prepared to make such an investment on an all out racing sailboat. Design knowledge from these Grand Prix boats could benefit the design of production sailboat's for those of us who are weekend Racer/Cruiser's or Cruising sailors.