well, given this sceneio, the last thing your going to do is a 90 degree turn. first, you shouldnt be overdriving the conditions or your knowledge of the area. but as we all know sh!t happens. at this point and at a high rate of speed, you have very limited options. 1 being panic and do noithing (definitly not prefered, but unfortunately routinely choosen) 2. make an abrupt but very small change in direction usually your best choice as the boat should respond to the steering input quickly and without upset as its a small change (bouys etc are not very big so it doesnt take much to miss them) 3. freak out and yank the wheel hard over and pray the law of enertia doesnt trump the physics of friction. remember the front of your boat is pointy, the side is big and flat it would be a lot safer to take a glancing blow than to broadside or barrell roll.I want to take a course and will at some point, however until then won't be doing any "race turns" but still would like to know "how". If I came flying up on a tree in the river or some thing and say a channel marker in front of that or whatever which would put me in a race type turn situation.
if racing is your actual intention, see tres, in the meantime, take a beach ball, tie a anchor to it and practice, go slow, increase your speed gradually, try different trims, try different conditions..keep doing it untill the boat is an extension of yourself, untill you can make it do what you want without thinking, then practice somemore because sooner or later its not going to react the way its supposed too, thats when the hours of practice matter. lots of practice..you get to change your shorts and it makes great conversation at the bar, not a lot of practice and generic trim settings..what do you want on your tombstone.. I have been racing various things since 88, sooner or later talent runs out and skill is the only thing that will save your butt.