In a laser tie your tiller so that the rudder is straight (don't lift/remove the rudder) then have fun with it. Try not to pick too windy a day for your first go
I don't think you could ever sail a Laser or in fact any una sailed boat without a rudder, you would just spin in circles. As Sailorchick says, you have to tie the rudder on the centreline to do rudderless sailing. It is the reason why windsurfers have skegs, you needsomething in the water to keep the hull tracking and resist the action of the wind on the sail. Rudderless gybing in a Laser would be very interesting, I think you would either never stop going from one gybe to another, or gybe, and round up head to wind.
In 2 man, 2 sail boats, you can sail without the rudder entirely, and the longer the boat the easier it is (again because of the hull's inherent desire to go straight) With 2 sails you can balance the boat (jib in to bear away, main in to luff up) as well as the body movement as previously described. It is also much easier with a centre board boat (using 1/2/ board) than a dagger board boat, as again the 1/2 board helps keep the boat in a straight line.
One thing sailing without a rudder does teach you, is the impact of the power of the mainsail leach. Pull the kicker on, pull the main in a bit and all you do is luff straight up into wind and tack. Personally I think sailing without a rudder is a practice for light air sailing, as you can really see what trim and body movement do, smoothness being the key.
This is actually getting away from the start of this thread, where the phrase "rudderless" is being used to describe minimising the use of the rudder. In roll tacking you want to just let the rudder follow where the boat wants to go. This is especially true in the first part in getting the boat to luff up, but then when you have the boat on top of you on the new tack, the bringing it back up to level again, is more about getting the mainsail through the air to generate the "squirt" forward you get when you sit on the side and sheet the main in, rather than minimising the use of the rudder.
You can sail a Laser in light winds without even having the rudder on the boat. The trick is having more cunningham on than you'd expect and then "steering" with trim and heel. Once you get the hang of it, it is an enjoyable drill. Without the cunningham tight, you'll stay in irons all day.
The reason that I think that gybing without a rudder may work ( and possibly be really fast), is that when I have managed to go into a fast gybe with a bit of windward heel I have felt an amazing feeling as if someone has grabbed the front of the boat and is dragging it around at speed- bearing the boat off. The first time it happened it blew my mind and I chickened out of the gybe because it felt so weird and out of control, now I am used to it it feels great and it produces a terrific gybe, amazing turning circle, no threat of a capsize and great speed out of the gybe. This is just like gybing a long board with the dagger board down, when you get enough angle on the board it bites and the board spins round. If you can do that to a 3.8m board (without a rudder) I can't see why you can't gybe a laser at speed without help of a rudder. I'm going to give it a go ( as soon as the water warms up a bit!).
However as per Mythbusters, all theorys should be tested ...
Interesting, but I can see why it works, pulling the cunningham on opens the leach, and pulls the draft forward so that centre of effort the sails is closer to the centre of effort of the hull, as basically the hull "spins" around the centreline of the dagger baord.
Have you tried sailing on a dead run without a rudder and controlled gybing, I just cannot think this is possible except in the very lightest of winds ?
Do not forget that even on a board you still had a skeg, and although not moveable, it is still providing lateral resistance, which you need to stop the hull rotating around the vertical axis of the daggerbaord.
Hence the practice that Sailorchick has done, where they tie the rudder on the centreline to do "rudderless" sailing.
However as per Mythbusters, all theorys should be tested, so please try it and report back. (I personally will not be trying it this weekend as the sea temp is a balmy 8 deg C in the UK)
Done and filmed doing it:
YouTube - Rooster Project 'X' sailing rudderless
Think of a windsurfer. The little fin in the back is only effective at speed and you can tack and jibe one in next to no wind. It's about adjusting or balancing the forces generated by the sail and the foil/hull-shape. Heel is one factor to change both, longitudinal movement of balast (you) is another.