Fred Pot, AIS man

Fred Pot copyright BenEllisonIt was an honor to be visited by Fred Pot last week. Fred is a Dutch marine engineer and consultant who’s been involved in AIS from the beginning. He currently lives on the West Coast, represents the U.S. on a couple of international working groups, and maintains He’s also started a company, SeaCAS, that’s about to introduce the SafePassage AIS receiver he’s holding at right (with an appropriate background of Maine fog, bigger here). The whole deal is inside the fiberglass tube: a dual frequency receiver with an AIS tuned VHF antenna, and a 16 channel WAAS/EGNOS GPS with its antenna. The four wire cable can either attach via USB for data to a PC, and power from it, or it can go to a small interface box with a power feed and 38.4kb NMEA 0183 output to a plotter/radar or a mix of displays. It’s going to cost $1,250 when it ships in August, but obviously is easy to install and needs no accessories. Other features: a receiver sensitivity rated at -107dBm, the ability to pass along all AIS messages, and the incorporation of dGPS corrections when within AIS range of differential ground stations. I’ll try to post a note when there’s more information and live ordering at, and I’ll have more entries soon based what I learned from Fred about the state of Class B and some surprising ways AIS may get used.

PS Yacht AIS, mentioned earlier, has released a final version of its Professional level software and is also now offering it bundled with a dual frequency TrueHeading AIS receiver/GPS for 729 Euros (you’ll also need VHF and GPS antennas).

Update, 6/7: Fred reports that while he was travelling, his engineers were able to “vastly improve SafePassage’s sensitivity by changing its appearance”. The new design will still be all-in-one but with an exposed whip antenna on top of a shorter pipe. He promises a picture as soon as available.

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now pleased to have Ben Stein as a very able publisher, webmaster, and editing colleague. Please don't regard him as an "expert"; he's getting quite old and thinks that "fadiddling fumble-putz" is a more accurate description.

8 Responses

  1. Daniel xie says:

    At half the price, we are about to announce a ais modem that can act as a simplified class a transponder or a class b ais transceiver, or a ais modem that under control of input commands, it may be used to act as a A to N.

  2. Eli says:

    That looks like a great product…but HUGE.

  3. GPSNavX says:

    GPSNavX Navigation software for OS X is SafePassage ready. Just plug it in and go!!

  4. Anonymous says:

    Huge – and expensive.
    Isn’t the idea of Class B transceivers to be under US$1000? If so, how many people will spend $1250 on a receiver only?

  5. Fred Pot says:

    Partially due to feedback received from major boating magazine editors, SeaCAS engineers have redesigned SafePassage to enhance its performance and make it lighter. All other attributes of the SafePassage solution remain as before, i.e. the easy installation, the ability to monitor both AIS channels simultaneously, the inclusion of a 16-channel WAAS enabled dGPS, the AIS and dGPS antennas, the necessary cabling and the MSRP (US$1,250).
    The change in appearance (see is a much shorter (approximately 12" tall) tube which, as before, houses both AIS receivers as well as the dGPS antenna. It now also houses a balun and has a 34" tall whip AIS antenna on top.
    A single coax cable connects SafePassage with a small box which converts the signal to the USB protocol for connection to a PC or a Mac or to the serial RS232 protocol for connection to a chart plotter. If the latter is used then the "converter" box needs to supplied with 12V or 24V DC because a serial connection cannot power the receiver. The converter box doesn’t need to be supplied with power if a USB connector is used.
    This redesign delayed production by about one month, still in time for the Annapolis Sail Boat Show on Oct 5th.

  6. George Phillips says:

    This sounds like a great little addition for my boat!
    Will you be at the Annapolis Boat Show (SAIL) in October? I’d really like to see this item up close and see how I could tie it in to my boat’s current system.

  7. Auspicious says:

    Looks like something didn’t work out:

  8. Ben Ellison Ben Ellison says:

    Another bummer! Fred Pot did a great service to boaters by tirelessly explaining the benefits of AIS. I’m sorry to see the doors of SeaCas close.

Join the conversation

Your email address will not be published. Required fields are marked *