I've been using my wetronome to ramp up my tempo when swimming consecutive sets at higher effort or faster speed (eg, 12 x 100m at 62 spm then 64, 66, 68 etc all the way to 84 spm). I find it easy enough to change the stroke rate between laps by tapping the wand against the unit under my swim cap. However, I have noticed that the unit doesn't always respond as expected if I try to change the settings while I'm holding the unit in my hand. Turning it off usually resolves things as I can start again from scratch when I wake it up. However, I have noticed that it is sometimes really difficult to turn off. I'm not blaming the unit (which is definately one of the best swim aids I've bought) and accept that I'm probably confusing it by tapping too many times, tapping in the wrong place or tapping in the wrong order...

I don't think it needs a screen, but I would like Mk 3 to have different coloured LEDs. How about red for stroke rate and green for lap mode? Not much use when swimming, but it would make it easier to see what mode it's in while setting it for the session.