Swim with your arms 100% straight (elbows completely locked) for the entire stroke cycle. This will result in a high elbow high hand recovery and improper pull mechanics underwater (the first part of your underwater pull will be pushing water down). So why on earth would we want to do this drill? Straight arm can help an athlete recover their arms high up over the top of your shoulder rather than low with your hand wide out to the side. You’ll have to roll your shoulders a lot to do this. Underwater this drill is going to make you produce a lot of force even though it’s in the wrong direction about half the time. We all know that a vertical forearm is important but a lot of triathletes will still swim with a dropped elbow and a less than vertical forearm. Straight arm drill at least forces one to have a vertical forearm at SOME POINT during the stroke instead of not at all. Stroke turnover will be slow when performing straight arm and that’s OK.