Doing some sea trials to the west of Browns island on Saturday, we were experimenting with heaving too so more or less stationary, when a fast moving 9 metre launch approaches from the NE.. My son alerted me to it and we noticed it was more or less on a collision course, I duck down and grab the air horn, but then it makes a minor course adjustment, I give it a squirt anyway as he is still going to pass uncomfortably close. No further course alteration was made and he passed approx 2 boat lengths from the stern doing an estimated 15 knots.....why ? I could not see the helmsman but that did n