Does everyone now have radar?

[NATBF]

Replacing standing rigging, so mast is coming out. This would be the time to add radar if I ever am... but it's a lot of money. And replacing rigging is already a lot of money. So:

Does everyone now have radar? I.e., is this a "just do it" situation, or are some fraction of folks here still running without radar? I have AIS transmit/receive, which works fine (and saved me in fog -- but the ships had AIS on), and a Davis/octahedral reflector. This is not a question of "is it nice", but "is it practically mandatory"?

--> Advice appreciated. And Happy Holidays!


PS: I ask because it seems maybe everyone just has it, and I am behind the curve:

Sleddog says (2021), "You don't navigate the CA and West Coast on a regular basis without radar. Period. And you don't need the radome way up in the air. 10 feet is fine for getting a reliable 4-8 mile view."

Tiger Beetle says (2020): " I'd minimize expectations of radar reflector performance (e.g., go with the Davis unit and call it good), not install an active radar-response device, install your own small radar with a guard zone alert function (Furuno 1623 = $1300)*, and if you have money left over install an AIS transponder with its own display (Vesper AIS Watchmate 850 = $625), and keep your AIS receiver until you have a transponder."

PPS: Very useful link on radar reflectors by AlanH: https://forum.sfbaysss.org/threads/radar-reflectors-musings.2425/
(My question above actually grew out of "what radar reflector to mount"... which led to "none of them are that great" and these links suggesting radar.)

* But if you have a chartplotter already, then... you are mostly stuck with that brand for your radar. Raymarine's are a lot more.

 

[tmsowerby]

I used radar during the SHTP. It didn't prevent a collision or help with navigation - but it could have. Using radar at night with guard zones activated gave me peace of mind and help me sleep. It was helpful in monitoring squalls. That said, the reality is that once you're out of the shipping lanes, you're not likely to encounter another vessel - except another competitor. Neither radar nor AIS will see a semi submerged shipping container.

Regarding AIS - reception and transmission are dependent on having the right VHF coax installed and ensuring that there's no source of interference. Some mast head tricolors will interfere with transmission/reception Take the opportunity to address this when the mast is down - whether or not you install radar. If you don't have expertise in marine VHF and electronics (I certainly don't) find someone who can help. Yev Ossipov at Farallon Electronics was very helpful with my B&G system and Vesper AIS.

Bear in mind the following as you make your decision:

• Not all vessels have AIS - and some that do, don't switch it on. Fishing vessels in particular.
• AIS is not real time - data is transmitted intermittently. This is important at close quarters.
• You cannot be sure that your class B AIS is being "seen" by shipping
• Radar is useful in monitoring squalls - especially at night - very helpful
• Overlay of radar onto chart is handy inshore
• Navigation bouys in poor visibility are not going to be exactly where charted due to tide, current or if they've been moved since the chart was updated. Radar will help you "see" them before you hit them.
• If you get radar, make sure you learn how to use it. In particular, learn how to:
  • adjust the various settings to balance sensitivity with specificity according to sea state and weather in general
  • set up guard zones
  • set up alarms
  • use automated target tracking and EBLs
  • use power save function to scan intermittently

Depending on your boat, you may be better off with a pole or backstay mounted radar rather than mounting on the mast. Less weight where you don't want it and sails and lines won't foul it. Consider a self-leveling mount as well.

Bottom line: it comes down to your comfort level, risk tolerance and bank balance. Radar is more than just "nice" but I wouldn't go so far as to say it's mandatory either. I honestly don't know if other SHTP competitors had radar or not.

Tim

 

[NATBF]

Thank you; that is very helpful, and much appreciated.

--> Any additional comments from you or others still welcome.


Afternote: I had certainly not thought of all of that despite having used radar before, and definitely did not understand this AIS transmission-periodicity issue. I has assumed AIS was good to something vaguely like GPS-level accuracy.

For any others looking, it appears that updates are speed dependent but can lag by a couple of minutes:
"Standard Class B CS Position Report: This message is sent every 3 minutes where speed over ground (SOG) is less than 2 knots, or every 30 seconds for greater speeds." (Wikipedia)
"Class A ships send position updates every 2 - 10 seconds depending on their speed and rate of turn, or every 3 minutes when reporting as anchored/moored and not moving faster than 3 knots. Class B ships send position reports every 30 seconds when moving faster than 2 knots, otherwise it drops back to every 3 minutes." (Vesper/Garmin)

I have experienced this effect, without realizing what was going on -- plotted boat positions would jump in surprising ways. Looking at the numbers, as a rule of thumb for how much position may jump, for a vessel moving at:
Class B, 6 kts, 30 sec reporting: distance change ~100 yards
Class A, 20 kts, 10 sec reporting: distance change ~100 yards.
Both are worse if the vessel is faster. For class B, it can be worse slower, too: 200 yds at 2 kts due to the shift to 3min reporting.

So AIS seems good for knowing what's around, but not as a radar replacement for tracking anything within a couple of hundred yards, despite how accurate GPS is.

 

[Critter]

I've been away from SSS for two years , but my most recent experience was that most of us didn't have radar. In the 2023 SHTP I felt quite safe with my AIS transponder.