Navigational Challenges

Once we had left the Leuven Canal we joined the major commercial routes to head West along major tidal rivers, the Rupel then the Sea Scheldt. We are close to the North Sea and the Rivers have fast flowing currents and tidal variations of about 6 metres. The minimum depth is ample at 2.5 metres but it is at times difficult to be sure how far the main channel extends. Regular ferries cross from one side to the other.

Why is this large aircraft sitting next to the river 20km outside Gent? We don't know!
We have experienced tidal conditions quite often in a sailing boat, but here there are additional restrictions such as tidal locks, bridges and intersecting rivers to say nothing of huge cargo barges moving very quickly where there are no speed limits. There are no locks on these river stretches, so we travelled a record distance of 108 kilometres (over two days) without any locks slowing us down. No wonder there are so many commercial boats using it.

Huge tiday lock gates which need to face two directions rather than the usual one
There is one tidal lock at the sea- end of each waterway. The "tidal" locks need to be two - way, so that they rise or fall dependent on the state of the tide. Some can only operate at certain times during a tidal period, otherwise the drop is too great. We turned up to one lock which seemed to operate at any time, but the keeper told us that he would only open it for us at high tide, an hour later, because that is when he thought it safe for us to continue our journey. These are the experts and they are very helpful (as well as speaking at least three languages) so we don't argue with their wisdom. Our documentation suggested that we wanted to go through the lock before high tide so that we would reach a certain difficult bridge at slack water, instead of which we got there an hour after high tide. Fortunately all was well and we made it through the surging water and angled narrow bridge in safety. the lock keeper was also thinking of our time at the next lock, which may well have been closed if we had turned up too early.  
On a tidal river there are extra difficulties to contend with. First was a bridge which had only 1.4 metres clearance at high tide, 2 metres too low for us. As it was a railway bridge we decided we would plan to pass under it when the level was more suitable rather than ask for it to be opened. We had already put people out enough that day with ten other bridge openings. We made really good time down that river, the Rupel, with the current on the falling tide then we arrived at the junction where the next river,the Sea Scheldt which was running the other way, so that we were fighting the rising tide. At that point we called it a day, to start early the next morning on the falling tide on that river. Finding a suitable place to stop is also a difficulty as they are few and far between on these fast flowing wide rivers.

Low Tide- the rocky bottom
To add to our challenges we have found that the charts and guide books for Belgium are far from perfect. Our Inland Waterways book lacks mileage information so we are left to guess exactly how many kilometres we need to travel between points. The chart we carry is a bit more informative but far from 100% accurate: it showed one distance as 2 kilometres when it was clearly over 20. At times David has had to resort to his phone GPS guidance system to be sure where we are and which way the rivers bend. He was especially pleased to have it when, an hour after we set off, a fog descended, significantly reducing visibility. There was no way of pulling over and stopping, so we had to hope that any of the large craft using the tide as we were would see us on their radar. Fortunately the fog lifted quite quickly.

4,000 tonne pusher and barge just overtook us
The tidal information is also poor: we have good programmes to show what time tides are at the major points on the coast but our guide book is quite inaccurate in giving the adjustments for places further inland. This makes it hard to know when the tide will turn so for planning on our final tidal stretch we resorted to eye- balls and twigs to judge when to leave the next morning. We cast off just after the turn of the tide and as hoped travelled with the tide for the next 50 kilometres to reach the last tidal lock. We were reassured about our calculations when two large commercials passed us just as we were leaving.

Best Regards,

Penny and Dave