1) Overview

The Lake Geneva Swimming Association (LGSA) Rules are a set of guidelines for those wishing to undertake an unassisted open-water marathon swim in Lake Geneva, Switzerland. Great thanks to all contributors for their continued support and collaborative spirit in promoting the love of open-water swimming. “I love not Man the less, but Nature more” - Lord Byron.

2) Purpose

These Rules aim to convey and promote the spirit of open water swimming, and to maintain a standard which has changed little since it was set by Captain Matthew Webb in 1875.

3) Definitions

Nonstop - Remaining in the water for the entire duration of the swim from start to finish without intentional physical contact with escort vessels, support personnel, or other objects (fixed or floating).

Unassisted - Without artificial assistance to performance, other than the standard equipment of the sport. Any swim that benefits from assistance - in the form of nonstandard performance-enhancing equipment, supportive contact with the swimmer, or other violation of the spirit of unassisted marathon swimming - is considered an Assisted Swim.

Natural Shore - In the case of Lake Geneva (Lac Léman) a natural shore includes the beach at Bains des Pâquis, further south of which, for reasons of traffic and water current, it is unsafe and forbidden by the local authorities to swim.

4) Standard Equipment

Standard Equipment includes equipment from the list below that has not been modified.

  • One swimsuit made of porous, textile material. For males, the suit must not extend below the knee or above the waist. For females it must not extend below the knee, onto the neck, or beyond the shoulder.

  • One standard bathing cap made of latex or silicone.

  • Goggles, earplugs, and nose clips.

  • Sunscreen and grease.

  • Safety lights for night visibility.

  • Simple timekeeping device (chronometer).

  • Escort boat, pilot, and crew.

  • Nutrition, and equipment to transport it between the boat and swimmer. The swimmer may not be supported or towed by the feed equipment.

  • Paddler(s) and support swimmer(s).

  • Observer(s).

The swimmer need not declare the use of standard equipment, rather it can be assumed. Any equipment not specifically listed here may be considered as non standard equipment.

5) Non standard Equipment

Non standard equipment is anything not specifically included in the list of standard equipment, or which is included in the list but has been modified, and can be categorised in two ways. Swimmers must declare the use of non standard equipment to the LGSA on registering interest to attempt the swim, regardless of any performance benefit or not.

Performance-enhancing equipment - this may be defined as non standard equipment that benefits the swimmer’s speed, buoyancy, heat retention, and/or endurance. Swims using such equipment cannot be considered unassisted.

Performance-enhancing equipment includes but is not limited to:

  • Equipment that may retain or increase warmth e.g. wetsuits, neoprene caps, booties, gloves.

  • Equipment that may increase speed e.g. flippers, paddles, shark cages.

  • Equipment that may increase buoyancy e.g. pull buoys, wetsuits.

  • Auditory pacing aids e.g. music players, metronomes.

  • Wearable electronic devices that transmit information to the swimmer and/or crew beyond the time of day and elapsed time.

  • Underwater streamers.

  • Performance-enhancing drugs on the World Anti-Doping Agency List of Prohibited Substances.

Non-performance-enhancing equipment - this may be defined as providing no obvious benefit to performance, but nonetheless is not considered part of the standard equipment of marathon swimming. Swims using such equipment may still qualify as unassisted, but the equipment must be specifically declared in the swim rules and documentation.

Non-performance-enhancing equipment includes but is not limited to:

  • Swimwear with increased coverage e.g. stinger suits, rash guards.

  • Wildlife deterrents. Note: harming marine wildlife violates the spirit of marathon swimming.

  • Wearable electronic devices that log data but do not transmit it to the swimmer.

6) Observers

The observer(s) must be capable of dispassionately evaluating the swim and its adherence to the declared rules. If an observer is acquainted with the swimmer, (s)he must be able to separate the personal relationship from his or her duties to observe, document, and verify.

Observer(s) must be informed about the rules, and understand the traditions, and spirit of marathon swimming, as well as the responsibilities of observing a swim attempt. Observers who have not attended an official training may also demonstrate expertise through their personal history in and/or affiliation to the sport - as a swimmer, crew-member, open-water professional, or administrator.

If a single observer is not able to maintain alertness for the entire duration of the swim, an additional observer is necessary. It is recommended two observers for swims anticipated to last longer than 18 hours, and three observers for swims anticipated to last longer than 36 hours. Overnight swims in the 10-18 hour range may also require a second observer. On swims with multiple observers, a lead observer should be designated to coordinate the observer team and documentation procedures.

7) Stroke regulated swims (see appendix A)

a) Declaring a stroke regulated swim

All stroke-regulated swim attempts should be arranged in advance with the Secretary of the LGSA, and will require extra payment to contribute towards the costs of the increased level of observation needed during stroke-regulated attempts.The LGSA shall stipulate the number of observers (and their qualifications/experience) which must be present for the swim attempt. Once a swim attempt is arranged with the LGSA to take place under a declared stroke, it may not be changed to another regulated stroke.

b) Authority of the observer

Each swimmer should maintain the declared stroke, according to the definitions outlined in Appendix A for each stroke. The declared stroke must be used throughout the period previously defined to the LGSA and it is at the observer’s discretion that compliance is being continuously attempted, the declared stroke being interrupted only momentarily and unavoidably by environmental circumstances such as wave action. At any time during the attempt the observer (as opposed to any other person fulfilling the observer’s duties on their behalf) has the full authority of the LGSA to enforce the Rules of the LGSA on their behalf and any decision taken by the observer shall be final.

c) Warning system

A coloured card system may be adopted during the swim attempt at the option of the observer to assist it with regulation of swim stroke as follows:

  • Each attempt (whether solo or relay and whether a single or multiple crossing) may be given up to 5 yellow card warnings for occasions of stroke deviation which are minor when considered separately or cumulatively.

  • A red card notice will be shown at any time a 6th stroke deviation has occurred whether or not considered minor and which takes place after 5 yellow card warnings.

  • A red card notice may be shown at any time irrespective of whether or not any yellow card warning has been given beforehand, if there has been a stroke deviation which in terms of the duration, nature and/or context of preceding deviations of any swimmer is sufficient to merit such action. Following the issue of a red card notice the attempt may not be treated for the purpose of ratification as any more than an attempt if it had been conducted from the outset solely as a standard, undefined and unregulated stroke-swim attempt, irrespective as to whether notification takes place or not (provided that, for a multiple crossing, any red card notice during a leg of the attempt will not prejudice an already successfully completed stroke-regulated leg during the same attempt).

If a coloured card system is not adopted then the observer may notify the swimmer/swimmers prior to the attempt of the observer’s alternative system, which the observer intends to adopt for issuing warnings for stroke-deviations considered to be minor in isolation and in the context of any other or all other deviations which have then occurred and issuing notice of disqualification for a stroke-deviation considered to be major in isolation or in the context of any other or all other deviations which have then occurred.

The observer’s interpretation of whichever system is adopted shall be solely within the observer’s discretion and the observer’s decisions (including those to relax or waive any provision) shall be final as between the observer and the swimmer. The observer’s relaxation or waiver of any provision shall not entitle any swimmer to expect any repetition or continuation of such relaxation or waiver. The observer (or any nominee, including the pilot) in the observer’s discretion may (but shall not be obliged to) video and/or photograph all or any part of the swim for the purposes of assisting with the observer’s adjudication of the attempt before, during or after the swim attempt.

d) Supported breaks/relay changeovers

To commence or end a supported rest break (being a rest break taken alongside the support vessel where feeding or other support can be provided by the support vessel to the swimmer) or relay-changeover of swimmers during the swim attempt, the declared stroke can cease to be used for the purpose of manoeuvring towards or away from the support vessel provided such manoeuvring is for a distance not exceeding 15 metres or as the observer determines is appropriate in the conditions. A swimmer may tread water and use any swimming style as part of the manoeuvring process.

e) Unsupported breaks

A swimmer may take an unsupported rest break during which time the swimmer does not approach the support vessel for support but stops all attempts to gain forward momentum. Where the observer concludes that the frequency, duration or nature of any break or breaks is contrary to the attempt being classified as a regulated attempt for the declared stroke then the observer can warn or disqualify the attempt as a regulated stroke attempt.

8) Swim Rules

These rules are an adaptation of the MSF swim rules which seek to make them specific and relevant to Lake Geneva, Switzerland and which do not in any way violate the spirit of unassisted open water swimming.

The declared Swim Rules must be read aloud by the observer in the presence of the swimmer and all support personnel before the swim begins.

a) Start and Finish

The swim begins when the swimmer enters the water from a natural shore. If geographic obstacles (e.g., cliffs) prevent the swimmer from clearing the water at the start, the swimmer may begin the swim by touching and releasing from part of the natural shore (e.g. cliff face).

The swim finishes when the swimmer clears the water on a natural shore, beyond which there is no navigable water (be it due to geography, safety or permissions). If geographic obstacles prevent the swimmer from clearing the water at the finish, the swimmer may finish by touching part of the natural shore.

b) Physical Contact

The swimmer may not make intentional supportive physical contact with any vessel, object, or support personnel at any time during the swim.

c) Standard Equipment

The swimmer may wear a single textile swimsuit with standard coverage, one latex or silicone cap, goggles, ear plugs, nose clips, and may grease the body. The swimmer may not use any additional equipment that benefits speed, buoyancy, endurance, or heat retention.

d) Drafting

The swimmer may not intentionally draft behind any escort vessel or support swimmer. The swimmer may swim alongside an escort vessel, but may not intentionally position him or herself inside the vessel’s bow and displacement waves, except while feeding.

e) Support Swimmers

A support swimmer (or swimmers) may accompany the solo swimmer for a limited duration. Multiple support swims are allowed, but should not occur consecutively. The MSF recommends a maximum of one hour per support swim and a minimum of one hour between support swims. Pilots and/or lifeguards may suggest support swimmers to stay in the water for longer periods if deemed necessary for safety reasons. The support swimmer may not intentionally touch the solo swimmer and must position him or herself at least slightly behind the solo swimmer. The pilot must agree to any request for a support swimmer before they enter the water to accompany the swimmer.

f) Authority on the Escort Vessel

The observer is responsible for documenting the facts of the swim only, and is not responsible for interpreting the swim rules. Any suggestions or advice from an observer should not be taken as official or endorsed by the LGSA. The pilot of the escort vessel (or lead pilot, if there are multiple vessels) is the ultimate authority in all matters except swim ratification, for which the authority lies with the LGSA. The pilot may cancel the swim at any time, for any reason, including, but not limited to, concerns for the safety of the swimmer or support personnel. The pilot is responsible for following all relevant local maritime regulations.

g) Responsible Environmental Stewardship

Everyone involved in the swim attempt - swimmer, observer, support personnel, and escort boat personnel - must treat the environment respectfully and prevent avoidable harm to marine wildlife and ecosystems.

h) Continuance of the Spirit of Open Water Swimming

If any issue regarding swim conduct arises that the Swim Rules do not clearly address, the swimmer should act - and the observer should judge - in accordance with the spirit of unassisted open water swimming.

9) Special Swim Types

Certain types of swims require additions or modifications to the standard rules for a one-way swim (Point A to Point B). Swimmers and observers should incorporate the indented portions below into their declared Swim Rules, as appropriate.

a) Multi-Leg Swims

A multi-leg swim is a swim that reaches one or more intermediate destinations (shores) before the final destination. The simplest form of a multi-leg swim is a two-way (“double”) channel crossing - a swim from one shore to a different, non-contiguous shore, and then returning to the first shore. However, a multi-leg swim need not return to the original shore. For example, a swim from Island A to Island B to Island C is also a multi-leg swim, with Island A to Island B as “Leg 1” and Island B to Island C as “Leg 2.”

For a multi-leg swim, add the following two rules:

  • After finishing one leg of the swim, the swimmer may rest for up to 10 minutes before beginning the next leg. While resting, the swimmer may be supported by a natural land mass but not by people or artificial objects.

  • Timing of the first leg begins when the swimmer enters the water and ends when the swimmer finishes the leg. Timing of subsequent legs begins at the end of the previous leg and includes any break on shore.

b) Relay Swims

A swim undertaken by a team of two or more swimmers, swimming in successive turns of a fixed time interval, in a fixed order.

For a relay swim, add the following two rules:

  • Relay teams may choose the number of swimmers (six is standard and the maximum is eight) and a turn interval of either one or two hours (one hour is standard), but the team roster, order, and interval must remain fixed for the duration of the swim.

  • The swimmer exchange takes place in the water, with the new swimmer approaching the previous swimmer from behind. The swimmers are allowed five minutes to complete the exchange, starting from the scheduled exchange time.

  • No support swimming is allowed on a relay swim.

Appendix A:

Defined stroke rules (as interpreted by the LGSA for open water swimming based on the rules defined by the CS&PF)


  1. The body shall be kept on the breast, underwater kicking on the side is not allowed and it is not permitted to roll onto the back, in each case as part of a process for achieving forward motion.

  2. Both arms shall be brought forward together simultaneously over the water and brought backward simultaneously under the water.

  3. All up and down movements of the legs must be simultaneous and, although the legs or the feet need not be on the same level, they shall not alternate in relation to each other and a breaststroke kicking movement is not permitted.

  4. The body shall not be completely submerged without the head breaking the surface at the appropriate point of each stroke.


  1. From the beginning of the first arm stroke, the body shall be on the breast. It is not permitted to roll onto the back at any time. The stroke cycle must be one arm stroke and one leg kick in that order. All movements of the arms shall be simultaneous and on the same horizontal plane without alternating movement.

  2. The hands shall be pushed forward together from the breast on, under, or over the water. The elbows shall be under water. The hands shall be brought back on or under the surface of the water. The hands shall not be brought back beyond the hip line.

  3. During each complete cycle, some part of the swimmer’s head must break the surface of the water. The head must break the surface of the water before the hands turn inward at the widest part of the second stroke. All movements of the legs shall be simultaneous and on the same horizontal plane without alternating movement.

  4. The feet must be turned outwards during the propulsive part of the kick. Alternating movements or downward butterfly kicks are not permitted. Breaking the surface of the water with the feet is allowed unless followed by a downward butterfly kick.

Source: Marathon Swimmers Federation