Composition overlay (Bottom hardness)

Select Composition from the Layers dialog to apply the composition overlay.

This overlay shows the bottom hardness map. Like vegetation, bottom hardness typing is more difficult on steep slopes than relatively flat bottoms. Confidence in bottom hardness classifications increases if you travel parallel along steeply sloping areas. Often bottom hardness is patchy, and the best maps are generated when the speed is slow.

The bottom hardness data generated is on a relative but continuous scale within a specific range. Soft bottoms include muck or loose silt or sand. Hard bottoms are compacted sand, gravel, and rock.