Granny Buttons is not the only daftly-named waterways site to use a webfeed. Apollo Duck, the boat advertising site, now offers RSS on its latest advertisements, allowing you to collect lists of the latest boats daily to your inbox. Ultimately it's only an advertising site, not a brokerage, so it can't offer the rich treats of, say, the Andy Burnett Narrowboat Brokerage (ABNB).
Webfeeds (RSS, XML, Atom, syndication - its names are starting to be legion) offers a way of delivering the web page to you as soon as it's posted, in a method akin to email, instead of you having to consciously visit the site. My own 'feed' is on the link marked "syndicate this site (XML)". If you don't know what this is, here's a primer from a blogger called Amy Gahran.
I recommend Feedster as a search engine for feeds if you want to find a feed quickly. (That's how I found about Apollo Duck's feed). But try this excellent article from the USC Online Journalism Review if you want to choose the various options. If you like the web and email, but you are sick of spam, don't ignore webfeeds - learn about them!
Expect Waterscape and other such general information sites to offer feeds soon. I do hope ABNB offers one, because the sheer sumtuousness of his presentation (and indeed of the boats) would be welcome in a daily dose, even if only for envy. Just look at boat No. 935, for instance!
Incidentally, it's hard to track Andy Burnett's weekly updates of boats for sale, not because there's any dross (there isn't) but because the basic site hides the individual page addresses and you can't easily find them again or save them for later reference. Here's a tip: To see the individual page addresses bookmark www.abnb.demon.co.uk as the main address.