It does seem that there are perhaps too many exclusively model boat shows. A 'good' one probably needs a couple of hundred models to be worthwhile and a decent area of water to play on - animation is vital in any exhibition.
For example the Ellesmere Port show seems to fill the bill quite well.
Perhaps there should be a condensation of shows to maybe three a year, one north, one midlands, one south. The boat groupies can drive hundreds of miles to all three, the saner ones just do the one closest.
I come to this conclusion as I was a railway modeller in the past and visited (and still do) many model railway exhibitions. There are dozens of these all round the country every month, but in contrast to boats a reasonable exhibition can be made with just a dozen or so layouts, since most train layouts are animated, and 5-10 traders, so it works.
And to those who say it's a place to meet acquaintances, etc - WRONG. That's a social event, not a public exhibition. (But I was brought up with the principle that if the host/hostess of a party was enjoying themselves, it probably wasn't a very good party.)