Bottom Composition Considerations for Bass Fishing

Bottom composition refers to the makeup of the immediate bottom not including objects found on the bottom called cover. Bottom composition is independent of bottom contours called structure. It is typically referred to as “soft bottom” or “hard bottom”.

Why is Bottom Composition Important?

Identifying fish on is important to:

Select Best Lure: While most lures can be worked on hard bottom some are more effective than others; where soft bottom composition can be problematic for many lures as they will collect the soft bottom material and no longer be effective.
Retrieve Techniques: Considering the use of hop and other retrieves on soft bottom to keep the lure off the bottom for longer periods of time and remove any bottom material on the lure. Conversely, the use of drag or other retrieve to keep the lure on the hard bottom.
Cover Considerations: Cover resides on both soft bottom and hard bottom, and bottom composition between cover is a common presentation consideration.

Bottom Composition Options

Soft Bottom

Soft Bottom Composition: Various types of very small sediment (smaller than sand) or soft organic materials, in some cases can look like mossy grass.
- Silt: Silty particles, smaller than sand (1/20 millimeter), fine texture that can contain some organic debris serving as food for some aquatic life. With current silt will move easily and decrease the water clarity. Silt bottom can look like sand.
- Organic Debris: Dead algae, plants, grass clipping, leaves, or animal waste can look like greenish muck.
- Mud/Muck: Thicker than silt but not enough to support most bottom contact lure.
Bass will Root Around: Bass will go into soft bottom if they sense forage under the soft bottom surface.
Bass Attracted to Bottom Disturbances: Some suggest bass will investigate a disturbance in soft bottom sometimes looking like a small puff of debris.

Hard Bottom

Hard Bottom Composition: From smaller rock (sand) to very large flat rocks that do not feature locations bass can use as cover. Hard materials such as:
- Gravel: loose aggregation of small rocks that do not provide cover, can be used for spawning, sometimes attracting bait fish or other fish to spawn.
- Large Flat Rock: More common on northern lakes that may have rock cover but typically void of grass or wood.
- Sand:
- Clay:
- Shell beds:
Wind/Waves: Wind blown structures, such as points and funnels/saddles, are more likely to have the silt blown off and thus hard bottom.
Roadbed Structure: Reservoirs with flooded roads are hard bottom composition.
Spawning Beds: Bass, and many baitfish, spawn on hard bottom that they have often created and maintained by removing the silt.

Bottom Composition Decisions and Influencers

Electronics: Most electronics will provide feedback as to bottom hardness and thus also be able to identify transitions.
Lure Feel: Most bottom lures will feel different when on soft bottom as compared to hard bottom.
Lure Evidence: Once a lure comes in contact with the bottom it will provide evidence of a soft bottom, for example a square bill crankbait.
Use Rod: If the rod will reach you can feel the bottom with the rod tip.
Sight Fishing: Look for visual indicators of soft versus hard bottom and transitions.