The type of bottom observed by echo sounder along the cruise tracks was classified according to its assumed suitability for bottom trawling as follows:
1. Even smooth bottom, likelely to be suitable for trawling.Figures 7-10 present the results with some interpolation between cruise tracks. Some uncertainty is then of course introduced since only a narrow strip of bottom has actually been observed.
2. Generally smooth, but more uneven bottom; care must be taken to select fishing path.
3. Rough bottom, unsuitable for trawling,
4. Very steep bottom, unsuitable for trawling.
A common feature along the outer parts of the shelf southwards is a strip of uneven bottom just inside the edge, such as seen off Baia dos Tigres. The slope of the shelf is generally in the south too steep for trawling. An exception is the part close to the border with Namibia. Also the sides of the canyons are very steep.
