Peter's Waterways Blog Tides above Gloucester This was first published in IWA West Riding's Milepost in September 2018, telling members that the occasional tide on the Severn above Gloucester is not just a minor change in the navigability of the waterway.

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This summer, as well as our usual canal trips we have had trips on three tidal waters, north, west and east of the country. Our western trip was on the River Severn. We navigated from Worcester to Sharpness and back with friends on their narrowboat Sapphire. From Upper Lode lock to the entrance to the Gloucester and Sharpness Canal at Gloucester, on some days of the monthly tidal cycle, there is a significant tide. We consulted the Canal and River Trust lockkeeper at Upper Lode who gave excellent advice to moor up at Lower Lode moorings for a couple of hours and then go downriver with the ebb tide, which he said was two metres over the weir at Gloucester on this morning. This tide had all the tree-covering brown swirling water, with its fair share of large logs, all threatening to jam the propeller. The tide was carrying us at about 9mph as we arrived at Upper Parting at Maisemore, needing to take the narrower East Channel towards the lock, rather than the larger West Channel to the weir.

Remembering the junction's layout from two earlier trips, a moored boat confirms the navigability of the smaller channel. We easily completed the turn, and then called the Gloucester lockkeeper on the VHF. The problem is that there is only one sign, a large motorway-type, and it is placed after the junction. It's just too easy to interpret all the markings as meaning to take the "next left". This could be uncomfortable, and difficult to return upriver and make progress against such a tide. Then there are those "3 miles". If it had been a motorway sign, then the junction (which you have in fact just passed) would be three miles ahead. It's trying to say that having taken the smaller waterway channel to the left, there are 3 more miles to the lock. The second-thoughts-small-additional-sign with a left-pointing arrow may cause sufficient doubt to enter the navigator's mind, to persuade them to take the proper turn.

Less dangerous is the sign for upriver traffic at Upper Lode. The main sign accurately shows the way to the lock, but it has another newer, less faded sign alongside, with a prominent arrow pointing towards the weir, with the small words "No Craft Beyond This Point". You couldn't make it up. Peter Scott @peterjohnscott