With more than 600 people on the water safety is a major consideration so Race Week uses sign to go afloat/sign that you have come ashore sheets pinned to a notice board. And because safety, and hence signing, is so important there are percentage points penalties for failing so to do.
Comparing signing sheets with each other and with results had been a lengthy process but now the sheets can be quickly data entered by just ticking boxes. This means that a competitor who was afloat but is not known to have come ashore can be quickly identified and the appropriate emergency procedures set in motion. It also means that those who simply failed to sign can also be identified and their penalties applied.