First, I'd like you to know that I'm a novice.
I want to record the moment that a competitive swimmer leaves a starting block, i.e. the instant the toes leave the block. As a basis of this, I'm thinking of using a piezo electric device, clamping this between the block and the pool deck, and recording the change of voltage.
An alternative idea is to use a light beam (laser) that would broken while the toes are on the block, and made when the toes just left the block.
Do you think any of these sounds like a reasonable way to proceed?
Thank you,
Douglas