This thread is a great example of why forum threads are not the best way to share this sort of information...
Rather than squabbling over the worst slips why not edit or add data to the boatlaunch database. Its a lot easier than I expected, you don't even need to register. Go to the site or if you are only interested in slipways then JK's new http://rib.net/boatlaunch
is definitely an easy way to go.
Then zoom in the map to where your slipway should be (the default setting is to zoom in to where you click so zooming is v. easy). If its missing - add it
(this will be rare). Click "Add place" at top left of map, then slipway>Go, then keep clicking the map to zoom in until you get a "marker" - you can click again to move/fine position it. Add the detail and then click upload (and follow very easy instructions) to put a photo on if you have one. And submit it.
If it is already there and you can enhance the listing
then click the marker point, then "read more". Then click "Edit place" (at top of map). Then edit details or add a photo. Unless the info is 100% wrong it is obviously better to add more than simply delete what is there. Obviously submit your changes so they are saved.
If you need to have a discussion here on the merits of a particular slipway then you can refer back to it - unfortunately there is only space for one weblink per slip (perhaps this is something Geoff can look at) - but you can include a link in the text fields for cut and paste.