Varieties of Nonstandard Equipment

Nonstandard equipment is anything not specifically included in the list of standard equipment. While it is impossible to exhaustively list all potential nonstandard equipment, we can categorize them as either (1) performance-enhancing, or (2) non-performance enhancing.
Regardless of the performance benefit, swimmers must always declare use of nonstandard equipment in their swim rules and documentation.
Performance-Enhancing Equipment
Performance-enhancing equipment is defined as nonstandard equipment that benefits the swimmer’s speed, buoyancy, heat retention, or endurance. Swims using such equipment cannot be considered unassisted.
Examples of performance-enhancing equipment include:
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 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
Non-performance-enhancing equipment provides 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.
Examples of non-performance-enhancing equipment include:
Swimwear with increased coverage - e.g., stinger suits, rash guards.

Wildlife deterrents - e.g., shark shields, shark divers, jellyfish sweepers. Note: harming marine wildlife violates the spirit of marathon swimming.

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