Johno, to see it live from a vantage point behind the start line, most get going without too much drama. There is of course the odd crash that takes out a few and a scramble to get going again. But all in all most get away unscathed. The front guys are well gone when the next line hit the water as you can see by the second photo.
They are however, very tightly packed on that beach waiting to go.

All 230+ of them between the white start tent in the back ground and the row of people in the foreground in second photo.
Spectacular to watch