Originally Posted by RichH
A tiller really implies that the rudder is a 'balanced' design so that the forces needed for the tiller when the boat is at high speed is light or easy to move.
A 'barn door' rudder, one that attached by 'hinges' to the end of a full keel or to a 'skeg' require a LOT of force to turn when the boat is at speed ... and functionally they are best turned with a 'wheel' that can generate a lot of mechanical advantage.
For a tiller the 'best match' is a 'balanced' spade rudder, the worst match-up would be a 'barn door' 'hinged' or pintle hung rudder. If the rudder is 'balanced' then the tiller will only need 'finger tip' pressure to hold the boat on a straight course but if the rudder is not 'balanced' sometimes you'll need arms like Popeye to overcome the adverse helm pressure when 'steering'.
Yes, if you want to buy with the idea of converting, then you want to make sure you pick a boat that the tiller was offered, otherwise you might wind up with a very stiff tiller. I would love to find a mid size boat with a tiller, mid to upper thirty footer, but not many are available.