Discussion has returned on the use of Class-B AIS data by commercial ships. For those unaware of the technology, Class B is an AIS system designed for use by boaters and is compatible with the Class A AIS units of large ships but with limited features.

One of the provisions the IEC, IMO and other regulatory bodies have included in the AIS spec is the ability for SOLAS classed vessels to filter out Class B targets. The general reasoning is that, if a large percentage of boaters adopt this technology then radar and ECIDS screens will become too cluttered to see important targets. Our friends at Panbo are currently figuring out the details but, according to the operating manual, it seems that Furuno’s latest radar units allow Class B targets to be slept (the AIS target is replaced with a less pronounced icon) or removed from the Display and you can also prevent Class B targets from sounding the unit’s CPA warning alarm.

What does this mean for professional mariners? A quick survey reveals that most mariners do not understand the full scope of Class B filtering settings and, therefore, leave these settings untouched. Most of us would agree that leaving settings we don’t understand alone is a good practice. And those that do understand the settings only use them in busy harbors.

This brings us to a word of caution. While Class B data can, and sometimes should, be suppressed in port it is important technology that will help us avoid boats which venture offshore. Therefore deactivating the display of Class-B targets on your ECDIS and RADAR is an action that should be logged and a note should be placed in your passage plan (or penciled next to the sea buoy on the chart) to remind all watchstanders to reactivate the setting once you have set out for sea.

The bottom line is that every watchstander wants to avoid colliding with a boat – but mistakes can happen. As technology improves, so will sound watchstanding practices to assure that navigation displays are sett-up properly. Until then, it is your responsibility to understand your equipment, understand it’s capabilities and potential faults, and create ship specific procedures to assure it is set up properly…. both in port and at sea.

A big gCaptain welcome to the 2,000+ new visitors that have stopped by gCaptain.com this week. The reason for the influx? Our CEO, Captain John Konrad,  wrote an article on AIS technology for the venerable magize SAIL. To read the article you will have to visit your local newstand and flip to page 64 of the magazine’s May 2008 Issue… but if it’s the information you’re after, John has shared most of it already with Panbo.com’s editor Ben Ellison, click HERE to read that post now.

Congrats to gCaptain contributer Richard Rodriguez for the recent syndication of his post on whaling protests by Reuters. Next stop a Pulitzer for his coverage of the Washington State Ferry dibacles on his blog The BitterEnd.

For more of gCaptain at the news stand be sure to check out the next issue of Sail Magazine for an article by our very own cp-founder, John Konrad (with much help and advisment from Panbo).

We have already proclaimed our love of AIS, the technology that helps watchkeepers identify surrounding vessel traffic, but currently this technology only lets us track large ships. This is about to change. Panbo reports that the USCG has asked the FCC to expedite approval of AIS-B systems for use on boats.

What is AIS-B?

The U.S. Coast Guard says;
Class B (AIS) is nearly identical to the Class A, except the Class B:

• Has a reporting rate less than a Class A (e.g. every 30 sec. when under 14 knots, as opposed to every 10 sec. for Class A)
• Does not transmit the vessel’s IMO number or call sign
• Does not transmit ETA or destination
• Does not transmit navigational status
• Is only required to receive, not transmit, text safety messages
• Is only required to receive, not transmit, application identifiers (binary messages)
• Does not transmit rate of turn information
• Does not transmit maximum present static draught

Got that?

You may have picked up on some Class B chatter over at Navagear or at Panbo questioning how effective these units will be in helping ships avoid small boats. Well Ben Ellison, electronics editor at Power & Motoryacht, Sail Magazine and Panbo.com has some questions for the ProMariner readers of gCaptain. He writes;

The bigger question is how much are they using AIS on their bridges?

Do they have good AIS target displays?

Are the displays getting too crowded as is, i.e. would there be a temptation to filter out Class B targets if they proliferate?

So with the goal of safer inland waterways for all we ask all professional mariners to answer the following poll questions then add your answers to Ben’s questions in our comments section.

Resources:

• AIS – Live Ship Tracking Map *NEW