You come upon an unconscious individual with a pulse, they do not appear to be breathing, you are unable to deliver the first breath, the next step is to repeat the head tilt/chin lift maneuver and attempt the breath again.
If they are unresponsive and not breathing, push firmly downwards in the middle of their chest at a regular rate. Ideally, you should alternate two rescue breaths with 30 chest compressions for anyone who has been rescued from drowning. This will help build up a supply of oxygen in their blood. If a person is not breathing and has no pulse, you need to seek emergency help immediately and be prepared to help the victim until emergency help arrives.