Marine Electronics, December 2022

SEA 235 marine SSB
The ICOM IC-803 with its color display that provides the user with all operational info in one place.

With all the advertising and dockside chatter surrounding satellite cell phones and the cost of monthly plans, it is comforting to know there are still active marine SSB nets for cruisers all around the globe. As a matter of fact, SSB transceivers, along with ham radios, are still the norm among offshore cruisers. 

However, because we offshore sailing folk do not (but should) comprise the huge customer base it takes to shape economies of scale, we are relegated to limited sources for some of our specialized electronics, particularly single-sideband AM radios. Which explains why three manufacturers — ICOM, Furuno and SEA — are our only remaining sources of marine SSB radiotelephones. 

The ICOM M802 and M803 transceivers offer 150W of transmit power through 830 channels, 160 of them programmable and 160 suitable for sending and receiving email. Of course, you will need a Pactor modem to complete an installation for email.   

The M803 also features an easily identifiable emergency distress button, which is encased in a spring-loaded cover, as on many VHF radios. The M802 offers GPS, GLONASS, speed and UTC data when the supplied GPS antenna is activated. The M803 has a built-in GPS receiver so no outside GPS is needed. And the M803 has 830 channels (160 programmable, 72 ITU SSN duplex, 249 ITU SSB simplex, 193 ITU FSK duplex, 160 email). 

Landfall Navigation recently has offered the ICOM M802 radio with AT140 automatic antenna tuner, along with a 10-meter-long OPC-1147N tuner control/power cable, for roughly $3,000, a good package for a good price.  

Both the M802 and M803 offer DSC scanning and calling, allowing 100 MMSI numbers to be stored for identification, just in case you need to hail a ship or shore-side emergency contact. Both units also feature NMEA 0183 connectivity, permitting interface with many chart plotters.   

The Furuno FS 1575 SSB radiotelephone offers a number of features making this model attractive to crews on both pleasure and commercial vessels. This unit provides access to an instant selection of 256 user-specified channels through the use of a rotary knob or direct keypad input and quick access to DSC messaging. 

On the FS 1575 face you will find a red DSC distress button, a numeric keypad for entering radio frequencies, and a readout screen providing such details as GPS position, talk and receive frequencies, options for daily test calling and a set of indicator arrows for message management. 

The list of options available for the FS 1575 includes an external speaker, printer and printer interface, antenna matching box, control unit and an AC/DC power supply. The unit comes supplied with a swivel base, which permits desktop or overhead mounting. 

To complete this short list of competitors, the SEA 235 is unique in ability to double as a standard SSB radiotelephone and a ham radio as well. With amateur bands still forming the central nervous system of the world’s offshore cruising fleet, this unique radio should be of great service. The radio set provides 150W of transmitting power on 1.6 MHz to 30 MHz, which covers most of the amateur radio frequency spectrum. 

By the way, if you do intend to communicate on the popular 20-meter and 40-meter ham SSB bands, you are required to possess an FCC General Class or higher license for those frequencies. After passing the requisite licensing exam(s), you will be assigned a call sign that will remain with you for life.  

Another feature of this agile, American-made transceiver is its AM receiver, offering what SEA boasts as “clear, undistorted reception of AM frequencies,” vitally important when communicating with a vessel in distress in the middle of a raging storm.  

Perhaps the most fascinating aspect of the SEA 235 is its small, unassuming profile, looking more like a nightstand clock radio than the robust, multifaceted communication beast lying within. At roughly $2,000, this radio is also a good deal for voyagers. 


Circumnavigator-author Bill Morris believes the best strategy for succeeding as an offshore voyager is to keep systems simple and, if possible, manual. Key to survival are a windvane self-steering system, a basic array of electronics and an aggressive alternative energy battery charging matrix. Bill is a frequent contributor to Ocean Navigator and the author of The Windvane Self-Steering Handbook (International Marine, 2004) and The Captain’s Guide to Alternative Energy Afloat (Seaworthy Publications, 2019).

By Bill Morris