By Mike Eades
West Valley RC Mariners, Litchfield Park, Arizona
Secretary, SeaWind Class Owners Association

Successful yacht classes and clubs sooner or later reach the point at which the number of entries for an event exceeds the number that they feel comfortable accommodating in one race and some form of heat system is needed. In Model Yachting Magazine Issue #134, published in 2003, there are three excellent articles describing the most commonly used Heat Systems:
  • Promotion/Relegation (Sometimes referred to as EORS, Equal Opportunity Racing System and now, officially, in its most up to date form as Heat Management System 2014 [HMS 2014], endorsed by ISAF Radio Sailing Division for international competition.)
  • Odds-Evens
  • Matrix System
Since that time a considerable body of experience with heat systems has been accumulated and I believe it is fair to say that the vast majority of US radio sailing regattas requiring heat racing use either HMS 2014 (or earlier versions) or Odds-Evens systems today. Excellent computer scoring systems have been developed and tested under field conditions for both these systems making each of them viable options for Race Committee use. Matrix systems now seem to have been phased out as they are cumbersome and difficult to adjust for skippers who withdraw and not readily amenable to computer scoring.At what point should a Regatta Committee consider splitting a fleet into heats? The answer primarily depends on local conditions such as visibility, distance of marks from the skipper control area etc. However somewhere between 10 and 20 boats per heat will be a practical limit beyond which mark roundings become a nightmare for skippers and Race Committee alike. The actual maximum fleet size set affects each system differently. For example, if the fleet maximum is set at 15 boats, HMS will accommodate up to 27 boats before requiring three heats whereas Odd-Even will accommodate up to 30 boats.

HMS 2014 (Promotion/Relegation)
Promotion/Relegation is a system in which after one or two seeding races the fleet is divided into heats, A, B, C, D etc based on either total or lowest Race Scores and it is determined how many boats (x) will be promoted/relegated (x is usually 4 or 6). The lowest fleet heat is run first and the top x boats are not scored but stay on the water and race in the next higher heat. At the end of this heat x boats are promoted and x boats are relegated and so on until the A fleet completes the race. The whole fleet is thus scored from top to bottom.

This system is the international standard, available as a computer based system and is used by the IOM Class and several others. HMS 2014 is a simple update to HMS 2013 which has a nice capability to produce .pdf versions of the score sheet at the push of a button if Excel 97 or later is used. The system is primarily designed for PC use and use on Mac computers is not recommended. Whether the scoring is done manually or using a computer-based system it is recommended that a Fleet Control Board is used to display and manage the heat promotion/relegation visually for all skippers to see. The principal current system administrator is Henry Farley, UK (

A brief description of HMS and a link, from which a zip file containing the latest versions of the System Description .pdf file and the full system Excel workbook file can be downloaded, can be found here: 2014.htm

A useful additional document from the HMS 2007 files describing the System Rules and seeding procedures can be downloaded here. If your club is contemplating using HMS for the first time and need advice the following experienced skippers have agreed to help: Barry FoxBob Piper

  • Pro - Arguably the most rigorous in determining absolutely a top to bottom finish order for each race. Can handle a large number of entrants if you are prepared to go to multi-fleets (>2). The voluminous Instructions which cover a wide range of eventualities, while seemingly complex, in practice can be run quite smoothly. Skippers will sail against skippers with a similar skill level.
  • Con - The system procedures do modify RRS somewhat especially regarding handling of protest and redress hearings which, if they potentially impact promotion or relegation, need to be dealt with promptly before the next heat can begin. It is possible for skippers who find them selves "on the bubble", continually being promoted and relegated, to sail a significantly greater number of heats than skippers who predominantly stay in one fleet or another which can be a burden.

Odd-Even System
This system, introduced from Europe in the early 2000’s was first used by the US Laser Class for the 2002 NCR and has since been adopted by the SeaWind Class as its favored heat system and used successfully in all NCR’s since 2007 and most Regional Championships. Our Club has used it for club events as well as major regattas. The system can be run quite easily in manual form but recently an excellent TWEAT (TWo-hEAT) computer scoring system has been developed by Carl Hansen ( and used successfully at several major regattas. The primary version TWEAT deals with two heats but a new version TWEAT ABc is now also available that can deal with one, two or three heats. The following documents describe the current systems:
The TWEAT Scoring Programs and Instructions:

in the Files section.If your club is contemplating using TWEAT for the first time and need advice the following experienced skippers have agreed to help: Al StiewingBob Piper

  • Pro - The manual system is very easy to run for small fleets using the special score-sheets. The line-up for each heat is called from the score sheet from the previous race. The new TWEAT Excel scoring system has been used successfully now in several events although minor updates are still being made to improve functionality and ease of use. Printed line-up and scoring sheets for the next set of heats were ready for RD use approximately 2 minutes after completion of the previous set of heats. The system shuffles the fleet from top to bottom based on the previous heat placings so each heat has a full range of skipper experience. All level skippers get to compete against the best and between heats can watch some of their peers and learn from watching what the top skippers do.
  • Con - Skippers of different skill levels will be grouped together.

Pond-side computer scoring
Many clubs are afraid to trust pond-side computer scoring because of concerns about system reliability, battery life, screen visibility issues, date entry errors etc. Both of the above described systems have built-in verification safeguards to recognize and flag data entry errors and take care of tie-breaking, discards and boats that withdraw or add in, after an event has begun, quite seamlessly.
While either system can be run using a laptop and manual score board, addition of a pond side printer can materially assist Race Committees with printed line-ups and score sheets. Printing and distributing a set of final score sheets to hand out to all skippers at the Awards Ceremony is a nice touch that skippers appreciate! System requirements:
  • Laptop computer with Excel
  • Simple printer (B/W or preferably color) & paper
  • 12v battery (hook-up to a conveniently situated car power outlet {max 100w!} or battery or use a portable RV heavy duty battery)
  • DC/AC inverter with cables and connectors for either car power outlet or direct to a battery. 2 AC outlets are desirable (Xantrex 851-0400 or - 0401 Power Plus 400W, $36-53 is an excellent example.)
  • Light shield box (wood or cardboard) capable of holding an open laptop with the open end facing the operator and not facing direct sunlig