… or nearly so. The locks of most of the canals we’ve travelled in the past have by-washes, so that if the pound above the lock has too much water, it flows down a culvert or channel around the lock into the pound below. Coming up the Grand Union from Brentford, and compounded by rivers joining and departing the navigation, several times we found water overflowing the lock gates. There’s a picture here.

In some cases the “bible” (Nicholson’s Guide) advises against mooring in certain pounds due to highly variable water levels. We’d avoided one such pound coming up to the summit, mooring a couple of pounds below, only to find the next morning we were thoroughly aground, and tilting over enough that the shower water didn’t stay in in the shower tray. With some pre-breakfast cursing and swearing, and the first ever use of the Song & Dance barge pole in anger we got waterborne and made it to the next lock. Dragged our bottom all through next pound, only to find that the following one – the one with the caution – had several moorers still afloat, plenty of water and no problems. Oh well…

The lockkeeper at Aylesbury also warned things were getting a bit difficult on the main line, as one of the back-pumping systems had gone U-S, and warned us about mooring in several other places too. But heading back up from Aylesbury, again we found plenty of overflowing water, apart from one pound where again we were dragging the bottom and were quite relieved to reach the lock at the end. (We subsequently found this pound had sprung a leak somewhere).

Coming back down the main line again, again there have been several pounds where the levels looked a little low, but not enough to cause concern. Fingers crossed there’s enough water to get us where we going…