A pacemaker is permitted only on solo swims in the English Channel by the Channel Swimming Association at the discretion of the pilot. Only one pacemaker is allowed in the water at one time. Pacemakers are not permitted to enter the water until the swim is at least 2 hours underway. Pacemakers are permitted to swim for up to one hour only and can only re-enter the water until another hour has passed.
Pacemakers are occasionally used during marathon swims across the Catalina Channel.