I get an email from YachtWorld everyday telling me about boats I want to buy but I'm not quite ready to yet and I rarely hit their website... well they've done a big re-skin adding new colors and layout to the home page.
In the search side of things, which is the feature I use the most they've added some new functionality to filter down your search results by clicking categories (New/Used, Boat Types, etc..) similar to many shopping sites. This new UI is just a new and admittedly cooler looking way to do the same searches you could do before.
I wish they'd update the information they collect about the boats so you could do more detailed searches like which electronic equipment is onboard and even better would be more of the measurables: displacement, beam, rig, etc.. so you can pick a boat by its potential performance characteristics.
Nice spiff on the site, but I'd wish they'd gone more into the functionality.