On Fri, 21 Apr 2017 18:28:32 +0100, Jeff wrote:

No. The above antenna is tuned for 144 to 148MHz. Marine band
transmit is from 156.0 to 157.5Mhz transmit, and 161.975 to 162.6Mhz
for AIS and weather. You might be able to retune the Jpole antenna in
the above article, but my guess(tm) is that VWSR at the band edges is
too high.

I think you are misinterpreting what this antenna is. It is not a J-pole.
It is basically 2 closely coupled dipoles one on 2m and the other on 70cms.
The drawing that looks like a j-pole is one half of the antenna ie an
element cut to 2m and the other 70cms.
Jeff

Oops. Y'er right. It's not a Jpole, although it looks like one. More
like a "fan dipole":
https://www.google.com/search?q=fan+dipole&tbm=isch
The 18.63" is 1/4 wave at 2m and 6.25" is 1/4 wave at 440Mhz. Thanks.

Incidentally, I forgot to mumble that one doesn't need two dipoles to
operate on just the marine band. Also, I can get similar performance
out of an 18" bow tie dipole antenna (and balun), or a biconical
porcupine:
http://802.11junk.com/jeffl/antennas/biconical/index.html

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558