AquaQuake: A draining function specific to Icom radios; a vibrating “buzz” clears water from the speaker grill.
Noise-canceling: Reduces background noise, so you can be heard and can hear more clearly.
PA/hailer and foghorn: Public address function allows users to make announcements from the mic like a loud speaker when an optional external speaker is installed. The foghorn emits horn sounds from the external speaker.
Waterproof ratings: IPX7 means the VHF can handle submersion to 3 feet deep for up to 30 minutes. An IPX8 rating means the unit can handle continuous underwater use.
Dual-watch scan: A channel scan mode that monitors channel 16 and another selected channel every few seconds.
Tri-watch scan: Monitors both channel 16 and two other selected channels while scanning.
Priority scan: Channel 16 is checked between every other channel during scan.
Memory scan: All VHF channels in the VHF memory are scanned from lowest to highest.
Normal scan: VHF channels are scanned in numeric order.
MMSI: Maritime Mobile Service Identity number. Boats are assigned one nine-digit MMSI for all onboard equipment capable of transmitting and receiving digital signals—EPIRBs, AIS devices, DSC-capable VHFs, INMARSAT satellite terminals, etc.—and that number serves as an identifier for the boat. The boat’s emergency contact info is linked to the MMSI, so when a distress call is broadcast, the info is included in the message, giving rescue and emergency personnel accurate details of the boat.
DSC: Digital Selective Calling; primarily a distress-alerting function. Users can send a pre-configured digital distress message (over channel 70) to emergency personnel and other DSC-equipped boats in their area. The message contains information about the boat and its owner, its MMSI number, the nature of the distress, and priority of the call. When a DSC radio is connected to a GPS, the Mayday includes the boat’s location. The transmission takes about one-third of a second and is automatically repeated until a rescue authority answers.
Class D DSC: Class D radios have two separate receivers, one for voice communications and the second for continuously monitoring channel 70 for any DSC calls.
