There is no rule that requires any mark but the pin to be in the water at the starting signal.

When I'm the race officer & the wind is particularly shifty, I'll get the weather mark boat in position, ready to drop. Then wait until there's less than two minutes remaining on the sequence before splashing the weather mark. Is it risky? A bit. Does it make the more fair? Probably. Does it save waiting time between races? You betcha.

I wouldn't consider abandoning until the competitors are reaching the laylines. Even then, if the mark is visible and not moving significantly, (like if the mark boat had wrapped the anchor line on the prop), I'd think real hard about abandoning the race. There are things you can do that will salvage the race, keep it fair and not confuse the competitors. (Anchor the mark boat and put the mark in the boat so it's very visible, put up the "M" flag and blow horns.)

In this particular case, the weather mark boat driver and his helper (wife) were very experienced sailors and were playing a passive-aggressive game with me - just to piss me off (it worked). The pin/gate boat boogied upwind - the WM boat radio magically started working when they got within a couple hundred yards and the mark had gone into the water as soon as they saw the pin boat heading to them. I don't think the competitors noticed it, since they had't gotten to the laylines yet.

My solution was to put a third person on the WM boat that I trusted to keep them from screwing with me.

BTW, this happens more often than you realize (both the late drop on the WM and passive-aggressive BS from mark boat operators).