What are people talking about when they speak of a boat's predictability?

that really depends on the person and the context in which it is brought up.

basically \"predictability\" is when something does not suprise you and you feel confident about what a certain feature is going to do.

it can be brought about by someone trying a new boat that is the same brand as their last boat, so they are used to the outfitting and general design style of the boat line.

it can also be brought about because a certain boat just happens to fit the paddler's style of boating, which can be hit or miss sometimes. (we all have a different style, even though we'd like to have some kind of ideal paddling style)

perdictability is good if you just want something familiar, but it is bad if you are looking for a new boat and you keep finding one that feels so close to your old boat that its not worth getting a new one.

Vague, I know, but it's hard to put a concrete definition on one word these days. You must consider the context and ask more questions so that you get as much information as you need to make good guesses.

Mostly it means it will behave the way you expect it to, whether its playboating or creeking, like not catching random edges or pearling for no good reason, also this normally means that it is pretty responsive.