18/11/2025
Why Pilotage plans are so important even in waters you know.
I recently arranged to meet a contractor who was going to do some work on our boat in Woodbridge Tide Mill marina, at the end of the River Deben on the East Coast. Woodbridge Tide Mill has a concrete sill at the entrance and at low tide the river just becomes a muddy ditch. As it would be a morning meeting I needed to be in the marina the night before.
HW was at 7.45pm so I drifted up the river as the sun set and took a waiting buoy outside of the marina. Waiting until I could get over the sill. I had calculated that I would just about have enough water at HW to get over.
However, when high tide arrived, I was surprised to see that the gauge showing the height didn’t show enough water was available but I tried anyway. Sure enough, I couldn’t get in. What I hadn’t taken into account was that the atmospheric pressure was very high (30 Millibars from the norm 1013 can make a foot difference) and the tide was 0.2 meters below forecast.
I was then the wrong side of the sill on a falling tide. This meant that within about an hour I was going to be aground and within 2 or 3 hours the boat would be laying on its side. Time was running out fast.
My only option was to return, in the pitch black, with no lit buoys, along a meandering river until I reached 24 hour water at the green No 7 buoy (see chart below). Without a pilotage plan it would be virtually impossible. Fortunately, although the river was well known to me, I still made regular pilotage hand drawn plans and was able to use one that I had prepared previously.
As anyone who knows the area will tell you the route was littered with moored boats that ground at low water and a lot of empty mooring that look like unlit buoys so identifying every buoy that I passed was crucial.
On a falling tide, I clearly didn’t want to go aground at any stage so armed with a strong light and my pilotage plan I was able to slowly navigate my way back.