Minor annoyance: when doing drills when you click the lower right button after to complete a set, there is a delay when the right upper button is unresponsive to confirm the distance. This is annoying for example when doing a set of 50’s drills or 50’s kick with a very short rest interval, since the watch is too slow or not looking at the watch when clicking.
Annoyance 2#: when sprinting freestyle the first 25 meters is often registered as fly.