Do you prefer an internal antenna over an external antenna? If so, this combo sonar & mapping iGPS is your best choice, with a 256-color, sunlight-viewable 640Vx480H pixel, high-res TFT display!
Ultra-bright, 5" (12.7 cm) diagonal screen
High-definition 640Vx480H resolution
Depth capability to 800 ft* (244 m) with 1500 ...