Marine GPS Units & Chartplotters

Pick a screen size that matches your helm space and viewing distance—smaller boats often use 5–7 inch units while larger vessels benefit from 9–16+ inch displays; higher resolution improves map detail and readability in sunlight and at steep viewing angles

Essential features include reliable GPS positioning, chartplotting with updatable marine charts, waypoint and route management, and a clear display; optional extras include built‑in sonar/fishfinder, radar integration, autopilot control, AIS target overlay, and networked sensors depending on fishing or offshore needs

If you plan to integrate radar, AIS, sonar, engine data, or multiple displays, choose a unit with NMEA 2000/NMEA 0183 or Ethernet networking to share sensor inputs and charts across devices; standalone units work for basic navigation on small boats

Entry-level units with basic chartplotting typically start in the low hundreds, mid-range systems with better displays and some sonar or networking cost several hundred to around a thousand, and high‑end integrated chartplotters with advanced sonar and networking can be well above that; the average across many listings is several hundred dollars

Basic sonar shows depth and returns on a single frequency, while CHIRP transmits a range of frequencies to produce higher resolution, clearer target separation and bottom definition; compare available transducer types, power, and frequency ranges when shopping for fishing capability

Plan for a secure mount, proper power wiring with fuse or circuit protection, and safe routing for transducer and antenna cables; keep firmware and chart databases updated, protect the display from prolonged UV exposure, and inspect connectors and seals periodically to maintain water resistance