Sonar & Maps: Contour Lake Mapping & Custom Charting

Before you ever drop the trolling motor, your contour map (等深线水图) eliminates 90% of dead water. Think of contour lines like a topographic mountain map, except going down into the lake.

Map FeatureWhat It Looks Like on ScreenWhat It Means Underwater & Why Fish Hold There
Tightly Packed Lines (密集等深线)Lines bunched right together like a barcodeSteep Drop-Off / Bluff / Ledge: Fish can move from 3 m to 9 m (10 ft to 30 ft) with two flicks of their tail—prime spring/fall highways
Widely Spaced Lines (稀疏等深线)Lines far apart with lots of open spaceGradual Flat (平缓浅滩/泥沙坪): Spawning flats in May/June and feeding flats where bass chase baitfish
Finger / Nose Jutting Out (向外凸出的尖角)Contour lines pointing out toward the main basinUnderwater Point (水下岬角/延伸鼻): The #1 smallmouth and largemouth ambush spot on any lake
Indent Cutting Toward Shore (向岸凹陷的弯角)Contour lines bending sharply inward into a flatInside Turn (内弯深坑): Deep water coming closest to shallow weeds—giant largemouth ambush spot
Closed Circles in Deep Water (深水独立闭合圆圈)Concentric rings surrounded by deeper numbersSunken Island / Offshore Hump (水下孤岛/暗礁包): Summer trophy smallmouth and walleye magnet

Three Map Settings You Should Turn On Immediately

  1. Shallow Water Highlight (浅水危险红色高亮): Set 0–1.2 m (0–4 ft) to Bright Red. Every shallow reef and shoal turns bright red so you never smash your lower unit when running on plane.
  2. Target Depth Range Highlight (目标水深绿色高亮): Suppose you catch two bass at 3.5–4.5 m (12–15 ft). Set your Depth Highlight to 12–15 ft (Green). Instantly, every hump, point, and ledge on the entire lake sitting at that exact depth lights up like a green ribbon!
  3. Live Contour Recording (AutoChart Live / Quickdraw / Genesis Live): On unmapped Canadian back-lakes, press Record while idling—your graph draws real-time 1-foot contour lines right onto your screen as you drive.

Top 10 in four markets

United States

  1. Humminbird LakeMaster PLUS High-Definition Card — $199. Aerial photography overlay, depth highlight shading, and water level offset; integrates with Minn Kota i-Pilot Link.
  2. Navionics Platinum+ Multi-Dimensional Cartography — $249. High-res relief shading, 3D view, satellite overlay, and 1-foot SonarChart HD contours for lakes and coast.
  3. Garmin Navionics Vision+ Premium Inland & Coastal — $249. High-res relief shading, aerial imagery, Auto Guidance+ path calculation on Garmin GPSMAP & ECHOMAP.
  4. C-MAP Reveal Lakes High-Definition Shaded Relief — $179. Ultra-high resolution shaded relief mapping brings hidden ledges, drop-offs, and humps to life.
  5. Humminbird CoastMaster Premium Coastal & Inshore — $249. Tide and current predictions, shaded relief, and custom color depth shading for coastal bays.
  6. Lowrance Genesis Live Real-Time HD Mapping — $0. Free real-time 1/2-foot contour mapping as you drive your boat; stores instantly on micro-SD.
  7. Navionics Navionics+ Standard Inland & Coastal — $149. The world's most ubiquitous marine cartography chip; 1-foot contours on 25,000+ freshwater lakes.
  8. Garmin Navionics Standard Inland Lake Charts — $149. Detailed 1-foot depth contours with daily map updates via ActiveCaptain app over Wi-Fi.
  9. C-MAP Precision Contour HD Regional Card — $149. Surveyed on-water by C-MAP hydrographers; high-density contours and pinpoint navigation hazards.
  10. ReefMaster ReefMaster 2.0 Custom 3D Mapping Software — $199. PC-based bathymetric sonar logging software; creates exportable 3D contour maps for Lowrance and Humminbird.

Canada

  1. Humminbird LakeMaster PLUS Canada Card — C$279. Aerial photo overlays and depth highlight reveal shallow rock shoals in Lake of the Woods.
  2. Navionics Platinum+ Canada & Great Lakes — C$349. Relief shading shows complex glacial drop-offs across the Canadian Shield in stunning clarity.
  3. Garmin Navionics Vision+ Canada Inland — C$349. High-res relief shading identifies deep humps holding giant smallmouth on Lake Simcoe.
  4. C-MAP Reveal Lakes Canada Shield Edition — C$249. Shaded relief mapping uncovers unmarked rocky humps in rugged northern shield lakes.
  5. Lowrance Genesis Live Canada Real-Time — C$0. Allows Canadian anglers to map remote unchartered fly-in lakes in real time with 1/2-foot precision.
  6. Navionics Navionics+ Canada Marine & Lakes — C$209. Comprehensive coverage of Canadian freshwater lakes, Ottawa River, and St. Lawrence seaway.
  7. Garmin Navionics Standard Canada Inland — C$209. 1-foot contours updated via ActiveCaptain Wi-Fi; shows seasonal water level offset changes.
  8. C-MAP Discover Lakes Canada Edition — C$179. Full-featured vector charts with high-res bathymetry and custom depth shading.
  9. Humminbird LakeMaster Standard Canada Card — C$209. Water level offset adjusts contour lines for extreme spring thaw and autumn reservoir drawdowns.
  10. ReefMaster ReefMaster 2.0 Custom Bathymetry — C$279. Enables creation of private high-resolution 3D bathymetric charts of secret home waters.

Japan

  1. Garmin Navionics Vision+ Japan Inland & Coastal — ¥38,000. High-resolution relief shading brings Lake Biwa underwater weedlines and ridges into vivid relief.
  2. Navionics Platinum+ Japan Inland & Marine — ¥39,800. 3D view and satellite photo overlay indispensable for high-pressure Japanese reservoir fishing.
  3. Lowrance Genesis Live Real-Time Mapping JP — ¥0. Widely used by Japanese tournament pros to create custom micro-contour maps of reservoir timber.
  4. Garmin Quickdraw Contours Japan Community — ¥0. Free community map sharing allows Japanese anglers to download accurate reservoir maps.
  5. C-MAP Reveal Lakes Japan Edition — ¥32,000. Shaded relief mapping uncovers intricate river channels and submerged bridge structures.
  6. Navionics Navionics+ Japan Freshwater Standard — ¥24,800. Detailed 1-foot contours on major Japanese tournament lakes like Biwa, Kasumigaura, and Ashi.
  7. Humminbird LakeMaster Custom Biwa Chart — ¥32,000. Depth highlight shading isolates the prime 4m-6m weedline zone on Lake Biwa effortlessly.
  8. ReefMaster ReefMaster 2.0 Japan Bathymetry — ¥28,500. Advanced bathymetric software used by Japanese guides to build proprietary 3D structure maps.
  9. Garmin Navionics Standard Japan Marine — ¥24,000. Wi-Fi synchronization with ActiveCaptain keeps navigational buoys and hazard spots up to date.
  10. C-MAP Discover Japan Coastal & Lakes — ¥22,000. Clean vector cartography with custom depth color palettes for Japanese reservoir rental boats.

China

  1. Garmin 佳明 Navionics Vision+ 高清浮雕阴影水图卡 — ¥1,850. High-res relief shading reveals underwater channels, sunken bridges, and rock piles in vivid 3D.
  2. Lowrance Genesis Live 实时半英尺等深线自绘系统 — ¥0. Zero-cost real-time mapping as you boat; creates ultra-detailed 1/2-foot contours on micro-SD.
  3. Garmin Quickdraw Contours 实时等深线与社区图库 — ¥0. Draws 1-foot contours in real-time; download and share thousands of domestic lake maps via cloud.
  4. Navionics Navionics Platinum+ 顶级多维水图卡 — ¥1,980. 3D underwater view and satellite overlay; reveals intricate drop-offs on large reservoirs.
  5. C-MAP Reveal Lakes 超清三维阴影浮雕水图卡 — ¥1,480. High-definition shaded relief brings hidden ledges and humps into razor-sharp focus.
  6. Humminbird 蜂鸟 LakeMaster 高清等深线与水位校准卡 — ¥1,680. Exclusive water level offset adjusts contour lines for seasonal reservoir water fluctuations.
  7. Navionics Navionics+ 标准版水图卡 (支持每日更新) — $1,180. Standard 1-foot contour mapping with Wi-Fi updates via mobile app for safe navigation.
  8. ReefMaster ReefMaster 2.0 专业水文数据三维建模软件 — ¥1,380. PC-based bathymetric sonar logging software; creates exportable 3D contour maps for Lowrance and Humminbird.
  9. C-MAP Discover 中国内河及近海矢量水图卡 — ¥1,150. Vector cartography with customizable depth color palettes for clean navigation.
  10. Garmin ActiveCaptain 智能船载互联与水图系统 — ¥0. Connects smartphone to Garmin chartplotter for wireless waypoint, route, and chart management.

2D Traditional CHIRP & Down View Sonar →

Sonar & Maps

How to read lake contour maps, 2D CHIRP, Down View, Side View, and Forward-Facing Live View—complete with dial-in settings and step-by-step fish-finding image interpretation.

  1. Contour Lake Mapping & Custom Charting
  2. 2D Traditional CHIRP & Down View Sonar
  3. Side View Sonar Tuning & Structure Identification
  4. Forward-Facing Live Sonar Calibration & Fish Behavior

Sonar & Maps