Last year I got rid of my windsurfing gear and got something called a
"Hobie Adventure Island": basically a kayak with outriggers optimized
for sailing.

About 220# beach-ready.

Hobie sells a set of beach wheels that work fairly well:

https://picasaweb.google.com/1081497...48948995878306

https://picasaweb.google.com/1081497...48951297106850

https://picasaweb.google.com/1081497...48949117328978

https://picasaweb.google.com/1081497...71011817870194

But the holes they mount into are so far back that the nose becomes
about a 50# lift. Not un-doable by any means, but it's not what I
would call easy on the back - and it has it's problems when a slope has
to be negotiated and something closer to the boat's balance point would
be a beeeeeg improvement.

To that end, I've been fooling around with a frame that holds the boat,
slides on-and-off the trailer, and has beach wheels mounted on it, but
it is flying in the face of the KISS principle and it seems like
embracing the existing wheels is the sensible thing to do.

That being the case, I started off thinking about a pack wheel/game cart
(as in https://youtu.be/4-gt-VF0zEI?list=PL76069A6D971DF3F9) but, once
again, I think I am going overboard on the complexity - not to mention
the price

The Bottom Line: Can anybody think of something off-the-shelf that
could function as a "Nose Wheel" for this thing?
--
Pete Cresswell