I believe that most people will be happier in the sort of kayak Jeff is describing than in a short, fat kayak.

I have peddled with several people in short kayaks on leisurely day trips who insist that they are happy with their kayak What happens quite frequently is that they can keep up reasonably well for the first hour or so. The problem arises if there is a bit of a headwind or adverse tide or current later in the day.

The paddlers in the efficient kayaks have probably been putting in about 70 percent effort for the first part of the journey, so have enough energy left to put in about 80 percent against the wind. In a short kayak they probably needed 80 percent effort to keep up in the morning so just can't manage 90 percent to keep up in the afternoon.

In a few cases that only needed to happen to them once before they bought a more efficient kayak.

Having a more efficient kayak is not necessarily about going faster. It can also be about getting to the destination with less effort or going further in the available time or even about having enough energy left at the end of the day to be safe.