Ouch! I fully expected your trip to be at risk. Some liveaboards have cancelled trips now due to rough seas. As to the timing, it depends on what the Captain decides, and sometimes the decision really is quite late. They may wait at times to see what radioed reports from other boats that have gone out earlier reveal. I can see how you'd be disappointed in the timing of the announcement of the cancellation, but here's the other side of the coin: it's possible that the delay was cautious, waiting for other reports all the while hoping not to have to cancel.... I've been on boats that have had to turn back, which is an even greater disappointment.