How should standing waves be handled?

[billgewater]

My standing wave experience was near Cape Don in the NT of Australia that nearly all circumnavigators will meet. I was motoring north at about 7 knots and the standing waves were about 2 m high and very close to each other. The water velocity over the ground was also about 7 knots and I was motoring into it.






The first thing I noticed was that sometimes these waves would bang into our transom with real ferocity. Then these waves would move through the hull form dragging the bow. (My vessel has a slack stern and buoyant bows - good for downwind cruising.) This effect was worst when we were moving backwards relative to the local lighthouse.
The other observation was that the pattern of waves seemed to move around, literally by 50 to 100 m, so predicting just where they would be worst or least was impossible to predict.
However we managed to pick a couple of smoother areas and finally got through OK. My mistake was attempting the rounding of Cape Don too close to the Cape and of course at the wrong tidal time.

[Cheechako]

Just avoid them. Many are tidal, avoid the area in max current. I have seem them like about a 3-4 ft high waterfall, just standing there. Huge tidal current in that area and the tides meet at the wave. It just sits there like a rolling wave in a long line with a few feet lower on one side of the wave. Only last for 10-15 minutes.

[Don C L]

After over 25 years as a river guide, I’ve seen and floated through a lot of standing waves, and what they all shared in common was the the wave was not moving, the current flowing through them was. The height, steepness and distance between standing waves AND whether they are breaking or not, AND the speed of the current are the measurements we need to answer the question well. Generally, motoring into one involves enough momentum to punch through the crest and fall to other side. Since you are going with the current, most of the momentum will come from the current itself so make sure you hit it straight and have enough power on to maintain steerage. If the wave is steep and breaking it is easy to get turned and capsized if you are not straight with enough momentum or speed. Going downstream it would take an unusually steep standing wave to have the prop come out since the boat’s momentum tends to punch it through more than over the wave, but be ready to pull back the throttle if needed as you ride over the crest. If you are going upstream don’t attempt it unless you have enough horsepower to overcome the current easily.

[Franziska]

This thread keeps reminding me of this video as a good, "horrible" example.
Surely would not want to be there!

https://youtu.be/ByGSMmenPDM