What lies beneath the surface matters enormously in carp fishing.
Bottom type determines food availability.
Depth controls comfort.
Structure creates movement routes.
Get these three right and everything else becomes easier.
The Major Bottom Types
Silt (Soft Organic Sediment)
Dark, soft bottoms loaded with bloodworm and invertebrates.
Carp absolutely love silt.
• Extremely rich natural food
• Fish root through it vacuum-feeding
• Common in protected bays and quiet corners
Tactics
• Use lighter leads (1.5–2 oz)
• Pop-ups or wafters stop hookbaits burying
• Expect cloudy water when fish are active
Silt = food.
Sand (Clean Hard Bottom)
Firm and light-colored with less natural food.
• Clean presentation
• Bottom baits sit perfectly
• Often found on windswept beaches
Best fished where sand meets silt or weed.
Sand provides presentation — not nutrition.
Gravel
Small stones with moderate invertebrate life.
• Crayfish common
• Excellent rig presentation
• Often in flowing water
Tactics
• Use abrasion-resistant leaders (20lb fluorocarbon+)
• Expect quality fish
Rock / Boulder
High-risk, high-reward.
• Crayfish and mussels abundant
• Extreme snag danger
• Common along Lake Michigan shorelines
Tactics
• Accept tackle losses
• Use 25lb+ leaders
• Apply strong pressure immediately
Weed (Living Vegetation)
Summer feeding magnets.
• Massive invertebrate populations
• Oxygen production during daylight
• Natural cover
Tactics
• Pop-ups essential
• Fish edges and gaps
• Heavy leaders
• Hit fish hard on hookup
Learning the Bottom with Your Lead
Simple but powerful:
Cast out and slowly drag your lead back.
You can feel:
• Silt – soft and mushy
• Sand – smooth
• Gravel – crunchy
• Rock – knocking / snagging
• Weed – resistance then release
This “lead test” tells you exactly what’s down there.
Depth and Carp Location
Shallow (0–6 ft)
• Dawn / dusk
• Night feeding
• Spawning
Medium (6–15 ft)
Most consistent zone.
Produces year-round.
Deep (15–30 ft)
• Summer heat refuge
• Thermocline zone
• Winter holding areas
Structure – The Underwater Highways
Structure funnels carp movement.
Points
Natural patrol routes with multiple depth options.
Humps
Isolated feeding areas surrounded by deeper water.
Carp navigate using them.
Drop-Offs
Instant access between shallow feeding and deep safety.
Prime holding zones.
Holes
Cool summer refuges and wintering areas.
Michigan Notes
Inland lakes:
Silt bays + weed edges dominate.
Lake Michigan:
Rock, mussels, crayfish, and steep drop-offs rule.
Best areas combine food + structure.
A silty bay with a nearby drop-off is carp heaven.
Key Takeaways
• Silt = food (use pop-ups)
• Sand = presentation
• Gravel = quality fish
• Weed = summer magnets
• Medium depth (8–15 ft) is most reliable
• Structure concentrates carp
• Learn the bottom with your lead
Next Steps
Continue with:
Watercraft & Conditions → Article 15: Weed Beds, Lily Pads & Aquatic Vegetation
https://michigancarp.com/watercraft/