Our recent foray up the Guadiana River was done without benefit of charts. Depths varied from ten to fifty feet (three to fifteen meters) and there was substantial current during parts of the tidal cycle. The current and depth present both navigation and anchoring challenges.
Lets take the nav issues first.
A basic rule which in our experience has held universally true is that the current runs faster and the water is deeper on the outside of curves. In the case of the bend shown above, which is where Wind Horse is anchored in the lead photo, at max current we saw two knots on the outside and almost nothing on the inside at anchor.
Depths were ten feet/three meters at anchor and twice this on the outside of the curve. One thing to watch out for are intersecting streams. These will usually create a shallower area off their entrances, even when they are on the outside of the curve.
Anchoring can present challenges, both from the drag of the current on the chain and its reversing nature. We like to set the anchor really hard in reverse, so if it becomes fouled it still has sufficient holding power.
You will often find that the river current will scour the bottom with a wall at the edge of the river, and it is possible to anchor quite close to the bank if desired. This gets you into a region of slower current and out of the traffic.
Finally, this type of navigation and spending time in the mud go hand in hand. Moving on a rising tide, with a kedge anchor and rode at the ready, will keep the situation under control.
Posted by Steve Dashew (August 12, 2010)
