Mooring in the Risle on way up the Seine to Rouen

The Risle is a small river that opens onto the south bank of the Seine about halfway between Honfleur and Tancarville. There is no development of any kind – it is as nature intended.
It made us an excellent starting point for the long run up to Rouen. If you would like to use it too – here are a few pointers from what we learned.
Just after you enter, a small stream enters from the right. Just after this, a small stony reef appears near low water and runs half way across from the left bank to about the mid of the river. This constrains the channel to the right half (looking up stream). It doesn’t look dangerous but it does take about 0.5M off the depth of the main channel.
We anchored with 25M of chain and a spade anchor. We initially anchored before the steam as the channel began to shallow quickly. Later as the tide dropped we realised that the main channel was towards the right bank and we could see the disturbed water upstream which later became the reef. We re-anchored about 50M above the upstream bank of the little stream and all was well. At low water (springs) we had about 1.9M water.
The bottom was mud – excellent holding and we came across no obstructions.
The current ran out strongly and at 1.5Kt and continued to do so as the rate of drop slowed and stagnated. Suddenly, as if someone had turned on a tap, it reversed still at 1.5Kt – with no discernable slack water. From then on it rose very rapidly. This occurred 3 hour after low water at Honfleur.
Our spade anchor absorbed both changes of direction without a whimper. If your anchor is liable to capsize, you will need to be vigilant.
We left a couple of hours before low water and had a hard run up the Seine to Tancarville – hugging the bank to get a current less than 3 knots against us. The up-going tide caught us up Tancarville and we reached Rouen in only a further 8 hours at 5.8Knots water speed.