
Humminbird HELIX 15 CHIRP MEGA SI+ GPS G4N with regions Card
Big Screen. Bigger Capabilities.
The HELIX 15 CHIRP MEGA SI+ GPS G4N delivers next-level clarity, power, and precision on a massive 15.4" LED-backlit display. This premium fishfinder/GPS combo features MEGA Side Imaging+, MEGA Down Imaging+, Dual Spectrum CHIRP sonar, and internal GPS with Humminbird Basemap—perfect for serious anglers who demand the best.
Top Features
MEGA Side Imaging+
Unlock structure and fish detail with unmatched clarity and extended range:
- 455 kHz: 405–505 kHz / 800ft side-to-side
- 800 kHz: 780–840 kHz / 250ft side-to-side
- MEGA: 1050–1175 kHz / 400ft side-to-side
MEGA Down Imaging+
See what’s directly beneath your boat with sharp, high-frequency imaging:
- 455 kHz: 435–535 kHz / 400ft depth
- 800 kHz: 800–860 kHz / 125ft depth
- MEGA: 1100–1200 kHz / 200ft depth
Dual Spectrum CHIRP Sonar with SwitchFire
Get precise arches and detailed bottom structure at impressive depths:
- Full Mode: 150–220 kHz / 1200ft
- Narrow Mode: 180–240 kHz @ 25° / 3500ft
- Wide Mode: 140–200 kHz @ 42°
- Power Output: 8000W (PTP), 1000W (RMS)
Precision Internal GPS (10 Hz)
Rapid position updates and accurate plotting with built-in Humminbird Basemap.
AutoChart Live
Create custom real-time maps with up to 8 hours of onboard recording.
One-Boat Network™ Compatible
Seamlessly integrates with Minn Kota and Cannon systems via Ethernet and Bluetooth.
Wi-Fi & NMEA 2000 Ready
Sync with the FishSmart app for wireless updates and connect to advanced boat data.
Specifications
- Display Size 15.4" LED-backlit
- Sonar MEGA SI+, MEGA DI+, Dual Spectrum CHIRP
- Side Imaging Range Up to 800ft (455 kHz)
- Down Imaging Depth Up to 400ft (455 kHz)
- CHIRP Depth Capability Up to 3500ft (Narrow Mode)
- Power Output 8000W (PTP), 1000W (RMS)
- GPS 10 Hz Internal GPS
- Mapping Humminbird Basemap, AutoChart Live
- Connectivity Bluetooth, Wi-Fi, Ethernet, NMEA 2000
- Networking One-Boat Network, Minn Kota, Cannon
- Mount Gimbal Mount
- Transducer Included (Transom Mount)
What's Included
- HELIX 15 CHIRP MEGA SI+ GPS G4N Control Head
- Transducer (Transom Mount)
- Gimbal Mount
- Power Cable
- Mounting Hardware
Compatible Mapping Cards (Sold Separately)
- Humminbird LakeMaster
- CoastMaster
- Navionics (Gold, Platinum+)
Smart VIP Price Promise
Our prices are very Smart at Smart Marine! Our Smart VIP Membership and committment to great deals makes sure of that, but if you find a lower price, tell us- we will match it!*

Price Promise Terms & Conditions
- Excludes limited time specials, clearances, non-stocked products, overseas websites, price comparison websites and eBay/TradeMe.
- Applies to identical products, in stock in NZ with pricing valid at time of price match request and purchase, with evidence supplied.
- Excluded Products: clearance, run-out, distress, damaged/soiled, parallel imported, non-stocks, trade quotes, commercial quantities, credit account holders, insurance claims, services, typos, overseas websites, price comparison websites, auction websites.
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- Short term finance may not be available with some price matched purchases. Please enquire.