I've done a boating holiday on the Broads, many, many years ago. A couple of points to keep in mind...
whoever you go with, you will get to know REALLY well (yes, even the husband) - make sure you're happy to be in close quarters with those folk for the duration. Even the biggest boat is still small.
Also, we went for two weeks; a week would have been enough - although we'd been married only a year or two at that point, we'd had enough.
And consider the weather - no guarantees it would be good.
On the upside, I saw a part of the country I'd never seen, we met some nice people, and the scenery was lovely (and we fed lots of ducklings - it was late spring or early summer).
If I had it to do over, I'd prefer to do a boating holiday where there was an aim in mind - to get somewhere, or to go to a festival, and combine the two.
Your call!