Si-Tex MDA-6 Class B SOTDMA AIS Transceiver 5W

The Si-Tex MDA-6 is a Class B/SO AIS transceiver built for boaters who want to be seen early and track other traffic clearly. AIS, or Automatic Identification System, is how vessels broadcast their position, speed, and heading to one another and to shore stations. A transceiver like the MDA-6 does both halves of that job. It transmits your own vessel's data so others know exactly where you are, and it receives the AIS signals around you so you can see nearby ships on a compatible chartplotter, tablet, or laptop. On a busy waterway or in poor visibility, that shared picture is one of the best safety tools you can add to a boat.

What sets the MDA-6 apart is how it transmits. It uses SOTDMA, a Class B/SO signaling method, and pushes out a full 5 watts of transmit power. That's more than twice the power of a standard Class B AIS unit. More power and smarter timeslot handling mean your vessel gets detected earlier and at greater distances, even when the airwaves are crowded with traffic. It also updates more often, so the position other boats see for you stays current instead of lagging behind your actual movements. The MDA-6 continuously broadcasts dynamic data including speed over ground, course over ground, and heading, giving surrounding vessels a sharper, more accurate read on what you're doing.

Connectivity is where this unit really opens up. It talks to your electronics over NMEA 0183, NMEA 2000, and USB, so it drops into both traditional and modern network setups. On top of the wired connections, the MDA-6 has integrated high-power Wi-Fi, which lets you view AIS targets right on a tablet or laptop without a dedicated display. There's no built-in screen on the unit itself, and that's by design. It feeds the displays you already own instead of forcing you to buy another one.

Setup and daily use are handled through Si-Tex apps. A Bluetooth programming app makes initial configuration and troubleshooting quick, so entering your vessel details and getting on the air doesn't turn into an afternoon project. There's also an AIS Control App with hazard reporting, so you can flag and share on-water hazards with a familiar, easy-to-use interface. It's a modern take on a piece of gear that used to be fussy to commission.

The MDA-6 ships with an external GPS antenna, which feeds the precise position data your AIS broadcast depends on. Accurate position in equals accurate position out, and that external antenna helps the unit hold a solid fix even when it's mounted below deck. Power draw is low, so the transceiver won't be a burden on your electrical system whether you're running the engine or sitting at anchor.

Si-Tex engineered the MDA-6 for real-world conditions. The housing is rated IP67, which means it's waterproof, dustproof, and vibration resistant, so it holds up in the damp, shaky places boats put electronics. It's compact and lightweight too, so you can find a home for it on just about any vessel without hunting for panel space. For the boater who wants dependable, high-priority AIS without the marketing fluff, that no-nonsense build is exactly the point.

It's certified to the standards that matter, meeting IEC-62287-2 and carrying FCC and USCG certification, so you can install it with confidence that it meets the requirements for AIS equipment. If you're upgrading from receive-only AIS or adding a transceiver for the first time, the MDA-6 gives you strong transmit power, flexible connectivity, and easy app-based setup in one compact box. See and be seen, and do it farther out.

One thing worth planning before you install is your VHF antenna setup. Like any AIS transceiver, the MDA-6 needs a VHF antenna to send and receive on the AIS channels, either a dedicated AIS antenna or a shared connection through a splitter with your existing VHF radio. Sort that out ahead of time and the rest of the install is straightforward. You'll enter your vessel name, call sign, and MMSI during the Bluetooth setup, and once you're programmed and on the air the MDA-6 quietly does its job in the background, making you more visible to the traffic around you every time you leave the dock.