Orders placed after 4PM on weekdays will not ship until the next business day. Orders placed after 11am Fridays will not ship until the following Monday.
Faster shipping methods may be available; just upgrade during checkout.
*Some exclusions apply.
Enter new zip code to refresh estimated delivery time.
The AS 21RD4KW 21" HD Radar from Humminbird helps you navigate through dark and foggy skies, busy shipping lanes, and less than ideal weather situations when used with a compatible fishfinder. The AS 21RD4KW can display a clear radar presentation or a chart display with radar overlay and target tracking. With zero-latency Ethernet connectivity, your compatible display will provide you with real-time target location and detection and long and short-range scales.
Dual Guard Zones
Establish up to two guard zones (sector or circular), and monitor any radar target within each zone.
Automatic Gain/Sea Clutter Control
See only what you need to with this dynamic filter that automatically or manually eliminates screen clutter caused by rain and sea returns.
Disable radar transmission over a defined arc to avoid the fly bridge area, or reduce reflections from fixed objects on your boat.
View the relative density of targets in eight different colors using this presentation option.
Adjustable VRM and EBL Functions
Adjustable VRM (Variable Range Marker) places an electronic mark or ring over a target on your radar display, and an EBL (Electronic Bearing Line) displays your relative bearing to the target.
AIS and MARPA Tracking
Automatic Identification System (AIS) electronically exchanges data with other vessels, helping to avoid collision. Mini-Automatic Radar Plotting Aid (MARPA) allows you to select targets and track their cource, bearing, and speed, also helping to avoid collisions.
ONIX8ci Combo ONIXC8ci SI Combo ONIX8ci NT SI Combo ONIX10ci Combo ONIX10ci SI Combo ONIX10ci NT Combo ONIX10ci NT SI Combo ION 10 ION 12 858c Combo 858c HD DI Combo 858c HD Combo 858c DI Combo 859ci HD Combo 859ci HD DI Combo 859ci HD DI Combo KVD 859ci HD XD Combo 899ci HD SI Combo 899ci HD SI NAV Combo 898c HD SI Combo 898c SI Combo 958c Combo 958c HD Combo 958c HD DI Combo 958c DI Combo 959ci HD Combo 959ci HD DI Combo 959ci HD XD Combo 998c HD SI Combo 998c SI Combo 999ci HD KVD SI Combo 999ci HD SI Combo 999ci HD SI KVD Combo 1158c Combo 1158c DI Combo 1159ci HD DI Combo 1159ci HD XD Combo 1159ci HD Combo 1198c SI Combo 1199ci HD KVD SI Combo 1199ci HD SI Combo 1199ci HD SI KVD Combo