Milltech Marine News

June 2023

Any questions about what AIS you should get?

Our AIS Comparison guide is an quick and easy way to sort through the marketing fluff and find the unit that fits your needs best. It has been updated for 2023 and can be found on the AIS Transponder product page or link directly here.

March 2023

Vesper Marine Cortex Gets Long Awaited Software Update

Cortex just got even better. Introducing the new and improved Cortex 2.0 software update. There's a new sleek user interface for Cortex handsets and some big improvements to core VHF functions to ensure you never miss a word. Cortex software 2.0 features new Squelch EQ

automated squelch with manual fine-tuning, omni watch multichannel scanning, and VHF audio recording and playback. Find out more here.

Same-day Shipping
If placed by 3:00PM EST, Monday through Friday, most orders ship same-day (excluding domestic Class B AIS which must be programmed before shipping).

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Use our online Shopping Cart to make sure your location is served and to check shipping options and costs. For more information, click here. Please call or email with any questions.

Aids To Navigation

How is AIS used on aids to navigation?

AIS transmitters can also be affixed to a floating or fixed aid to navigation (ATON), such as a buoy, beacon, or light. The AIS broadcast provides the position and purpose of an aid, such as a port or starboard lateral buoy, even before it is close enough to be visible from a ship or to provide a radar return. This can help mariners confirm their ship's position or to prepare to make a turn that is based on passing a particular aid.

Three types AIS ATONs

There are thousands of buoys and beacons in U.S. waters. A growing number of these are AIS ATONs, of which there are three types. The Coast Guard calls these “real” (or “physical”), “synthetic,” and “virtual.”

Real AIS ATON - A physical aid to navigation structure on which an AIS transmitter is affixed and from which AIS messages are broadcast.

Synthetic AIS ATON - A physical aid to navigation structure, without an AIS transmitter, but for which AIS messages are broadcast from another (usually land-based) location.

Virtual AIS ATON - An aid to navigation with no physical structure. It exists only through AIS messages broadcast from another location. A few uses of virtual ATONs include environments where buoys are moved seasonally, such as in sea ice, or where a marker needs to be placed quickly, such as to mark a newly identified isolated danger or wreck. These aids can only be seen on an Electronic Chart Display and Information System (ECDIS), or other AIS enabled display, such as a ship’s radar.

AIS ATONs on NOAA nautical charts are portrayed with a magenta circle, enclosing an ATON symbol. The same symbol is used to depict both real and synthetic AIS ATONs, with a magenta “AIS” label next to the circle. Virtual AIS ATONs have a “V-AIS” label. The table below shows examples of how non-AIS and AIS ATONs are shown on NOAA nautical charts.