On Sat, 22 Apr 2017, Fred McKenzie wrote:

In article , rickman
wrote:

Can you explain what would be preferable about the J-pole antenna? One
big disadvantage is that it appears to be more like 6 foot long for 2
meter use. That could be rather heavy and clumsy on a kayak.

Rick-

You are correct about the size. On the other hand, any separate antenna
for the VHF Marine band will be a bit clumsy on a kayak.

The "J" end of a J-pole is used to match a cable to the high impedance
of the end of a half wave element. One advantage of a vertical half
wave entenna is that it directs more energy towards the horizon,
compared to a quarter wave ground plane antenna.

Jeff Liebermann's analysis sounds like the best approach to VHF on a
kayak. But no matter which way you go, you are transmitting from a
point close to the water. You are limited to line-of-sight to another
kayak. Range to a base station will be mostly determined by the height
of the base station antenna.

And with a kayak, the issue is less about "antenna gain" than that there's
nothing with height on a kayak, and it's very low in the water.

Figure out some sort of "mast" and the problem is close to solved. Once
you have height, the actual antenna type matters less. I seem to recall
George Dyson put sails on some of his really big kayaks, so that's an
option, and the mast would provide some height for the antenna.

Michael