Navionics and Colregs

I have Navionics Boating HD app on my tablet and I was doing some pre-planning for an upcoming trip from the Ionian Sea to Turkey through the Corinth Canal. The Saronic Gulf around Athens is a particularly busy area and there is an established Traffic Separation Scheme there. I used auto-routing on the Navionics app and it has me crossing both lanes and the separation zone of the TSS at an angle of about 45 degrees. Surprised I e mailed Navionics and asked
"[FONT=Arial,Sans-Serif]If I set an automatic course does the course you plot for me take account of Colregs for instance in relation to traversing or crossing a TSS."
I got a reply yesterday which said
[/FONT][FONT=Arial, sans-serif]Dock-to-dock Autorouting takes COLREGS and TSS into account to calculate the route accurately and safely. It quickly creates detailed routes even through narrow waterways and channels, based on chart data and navigation aids.
[/FONT][FONT=Arial, sans-serif]I went back to them with a screenshot of the route and added[/FONT]
[FONT=Arial, sans-serif]"I had assumed your auto routing would take account of Colregs and TSS but when i used auto routing to plot a course through the Saronic from Corinth to the Island of Kea it has me crossing the TS line at an angle of about 45 degrees whereas Colregs require that " A vessel shall, so far as practicable, avoid crossing traffic lanes but if obliged to do so shall cross on a heading as nearly as practicable at right angles to the general direction of traffic flow". I would be obliged if you could explain this apparent anomaly".
They replied:
[/FONT]Thank you for the screenshot. This is certainly something that we will investigate further. If you could, please provide your start and end coordinates for testing purposes on our side. This way we can determine the best resolution. Thank you for your kind cooperation.

I'm curious if anyone else has had similar experiences with Navionics auto routing?

Please explain TSS. Can it be assumed you are not supposed to cross the lavender bar?

Okay, found a rather vague description of it on Wiki, but still not sure understand what it means for recreational boaters.

Donsan said:

Please explain TSS.

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Traffic Separation Scheme See COLREGS 10 COLREGs course - Rule 10 (Traffic separation schemes)

Donsan said:

Please explain TSS. Can it be assumed you are not supposed to cross the lavender bar?

Okay, found a rather vague description of it on Wiki, but still not sure understand what it means for recreational boaters.

Click to expand...

Some vessels are required to participate in the TSS and for the most part they must "stay in the lanes". All vessels, recreational as well, are required observe the TSS rules.

If your boat is under 20 meters then you are generally not required to participate in the TSS. There is no special consideration in rule 10 or any other colregs rule given for recreational vessels. If you are not required to participate in the TSS then in simple terms you must:

• Not impede the movement of a vessel required to participate. This is generally construed as you should not force a TSS participant to give way to your vessel.
• Should if possible not operate in the lanes.
• Should if possible cross the lanes at close to 90 degrees as you reasonably can.
• The magenta line between the lanes is called the separation zone or separation line and all vessels should stay clear except to cross the separation zone.
• Be very cautious around the 'ends' of the TSS

It is also important to know that each port state creates it's own specific TSS rules that go beyond the basics laid out in rule 10 of the colregs. When boating in a high traffic area it is best to get a copy of the current local TSS rules.

The shipping pilots make heavy use of the TSS. The TSS's are generally managed by local authorities over VHF somewhat like air traffic control but more of an advisory service than a control authority. The local rules will specify which VHF channel(s) for given areas. Listening to the VHF channel, observing AIS and with local knowledge you will get a very good 'picture' of what the heavy ships are up to making your crossings and navigating near busy harbors much less stressful.

Irish Rover said:

I have Navionics Boating HD app on my tablet and I was doing some pre-planning for an upcoming trip from the Ionian Sea to Turkey through the Corinth Canal. The Saronic Gulf around Athens is a particularly busy area and there is an established Traffic Separation Scheme there. I used auto-routing on the Navionics app and it has me crossing both lanes and the separation zone of the TSS at an angle of about 45 degrees. Surprised I e mailed Navionics and asked
"[FONT=Arial,Sans-Serif]If I set an automatic course does the course you plot for me take account of Colregs for instance in relation to traversing or crossing a TSS."
I got a reply yesterday which said
[/FONT][FONT=Arial, sans-serif]Dock-to-dock Autorouting takes COLREGS and TSS into account to calculate the route accurately and safely. It quickly creates detailed routes even through narrow waterways and channels, based on chart data and navigation aids.
[/FONT][FONT=Arial, sans-serif]I went back to them with a screenshot of the route and added[/FONT]
[FONT=Arial, sans-serif]"I had assumed your auto routing would take account of Colregs and TSS but when i used auto routing to plot a course through the Saronic from Corinth to the Island of Kea it has me crossing the TS line at an angle of about 45 degrees whereas Colregs require that " A vessel shall, so far as practicable, avoid crossing traffic lanes but if obliged to do so shall cross on a heading as nearly as practicable at right angles to the general direction of traffic flow". I would be obliged if you could explain this apparent anomaly".
They replied:
[/FONT]Thank you for the screenshot. This is certainly something that we will investigate further. If you could, please provide your start and end coordinates for testing purposes on our side. This way we can determine the best resolution. Thank you for your kind cooperation.

I'm curious if anyone else has had similar experiences with Navionics auto routing?

Click to expand...

I am of the opinion that the Navionics auto-routing feature is terrific as a STARTING point. IMHO a prudent captain must examine the route closely to ensure every aspect of the route is safe.

catalinajack said:

I am of the opinion that the Navionics auto-routing feature is terrific as a STARTING point. IMHO a prudent captain must examine the route closely to ensure every aspect of the route is safe.

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Totally agree and that’s why I questioned it when I saw a potential problem. I have no intention of following the suggested route across the TSS but it’s worrying that Navionics think their software takes account of the TSS and COLREGS.

Irish Rover said:

Totally agree and that’s why I questioned it when I saw a potential problem. I have no intention of following the suggested route across the TSS but it’s worrying that Navionics think their software takes account of the TSS and COLREGS.

Click to expand...

I would take the auto routing by Navionics as a great start. From there when you approach the TSS, you MUST bear the COLREGS in mind and adjust your route accordingly. Navionics is not giving you the only option for your route. Nor will Navionics be there as a Co-Defendant when your neglect to follow the COLREGs in favour of the suggested Navionics route gets you into difficulty.