On 17-Mar-2005, "Tinkerntom" wrote:

Did you follow my suggestion about using 2x4 runners that would extend
further to the front. Most of the standard rack, are only 4 or 5 ft max
between cross bars. That leaves alot of a 18 ft double or longer,
unsupported.

There's no point in supporting the hull further apart than half its length.
For an 18 ft kayak, that means no more than 9 ft between crossbars.

Realistically, four or five feet between crossbars is plenty. If it gets
much longer, rocker might get in the way. You should be tying down the
bow and stern anyway, so you'll be providing plenty of support for
the vessel against wind, bumps etc.

Mike