VHF-Activated Fog Horn Signals

Jul 27, 2011
5,134
Bavaria 38E Alamitos Bay
I've belatedly learned that the USCG system of coastal fog horn signals has been "upgraded" from automatic to user-activated. Evidently, the coast of Maine where there is a lot of fog was the first area to be so upgraded. The system has now been implemented in southern California as well as of May or June, 2016. If it's foggy out and one needs to hear a fog signal, etc., the mariner keys the VHF on channel 81A (at this location) five times within ten seconds to receive 30 min of fog whistles from shore. I have not tried it b/c I don't wish to set off the harbor's fog horn unnecessarily nor have I been in fog at anytime this year. A vessel is supposed to be out on the water, in fog or approaching some, and on the normal "line of sight" of the fog horn, to activate it. Has anyone used this system?:what:
 
Last edited:

Rick D

.
Jun 14, 2008
7,182
Hunter Legend 40.5 Shoreline Marina Long Beach CA
No problem. I'm sure all of us recreational boaters will remember that just fine in six months when the fog comes in to SoCal... :cuss:
 
  • Like
Likes: Parsons
Jul 27, 2011
5,134
Bavaria 38E Alamitos Bay
There's some fog hanging at the harbor entrance today at Ventura. I heard the horn go off a while ago, but it's stopped now even though the fog is still here. So, somebody likely testing or using the VHF-activated system today! I guess it's working.
 
Last edited:

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,744
CAL 35 Cruiser #21 moored EVERETT WA
I went and looked at the charts for the PacNW in an area of regular fog formation. No indications on the charts that the MRASS system is in place. How is that pronounced?
Guessing you could test the system whether there is fog or not as the system is designed to replace an aging system that is having difficulty knowing if fog is present.

Automation. Stealing all the good jobs. Job Opening "Sit on a sun struck headland, mild breezes, and turn the horn on or off depending on the weather. We provide nifty uniforms, wifi, and plenty of coffee. " What more could a person want?:biggrin:
 

DougM

.
Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
There is a VHF activated fog signal at the lighthouse near me. It seems like some boneheaded powerboaters think that its great sport to pass by and activate the horn, generally in the middle ofa bright sunny day,
 
Oct 9, 2008
1,742
Bristol 29.9 Dana Point
We have it now in Dana Point. Harbor patrol used to manage it. When fog, we got the fog horn.
Now:
1. Morons constantly activating it unnecessarily.
2. When the fog does roll in and I'm out in it, I won't remember how to use it. Although, probably someone else will, or I can radio harbor patrol to start it for me.
 
Jun 8, 2004
2,925
Catalina 320 Dana Point
Long Beach, Newport and Dana Point are also 81A so one can only hope ALL of them will be the same, now I just got to post it next to the radio or I'll forget in a week, again.
BTW the rationale for the change is that the current automatic systems were built in the 30's and are difficult to repair. Really ? 2016 and no one can make something to trigger a foghorn when humidity is high and visibility decreased ?


Why is the Coast Guard converting lighthouses to MRASS?

The existing VM-100 fog detection system is antiquated, unreliable and inefficient. Spare parts are also extremely limited and no longer being manufactured.
 
Last edited:
Feb 2, 2010
373
Island Packet 37 Hull #2 Harpswell Me
Here are the newly automated Maine lighthouse. They were previously automated but it was not reliable, there are still some lighthouses the blow all the time.
 

Attachments

Rick D

.
Jun 14, 2008
7,182
Hunter Legend 40.5 Shoreline Marina Long Beach CA
Interesting, in SoCal, where the radio range intersects several harbors with automated horns, how do they discriminate?
 
Jan 18, 2016
782
Catalina 387 Dana Point
We have it now in Dana Point. Harbor patrol used to manage it. When fog, we got the fog horn.
Now:
1. Morons constantly activating it unnecessarily.
All the time. Like all day, every weekend. Nice and sunny out, and the horn is blaring away. It's kinda annoying.

I'm also in the camp of a fog sensor would be a pretty simple device.
 
  • Like
Likes: Rick D
Nov 6, 2020
363
Mariner 36 California
I know this is an old post but so many people still seem ro not know about this.

Santa monica bay / marina del rey is 81A. Working. We tried it a couple weekends ago.
 

RoyS

.
Jun 3, 2012
1,742
Hunter 33 Steamboat Wharf, Hull, MA
If I were to guess, I suspect this change was based on the idea that wealthy coastal home owners do not want to hear fog horns. The idea then is to only activate the horn when a boat off shore actually needs it; so have the distressed, fog bound boat activate it only when needed. Similar issues around here with train whistles at railroad crossings. Lots of complaints about airplane noise from communities around Logan Airport. Some communities are banning leafblowers as well. No one likes noise.
 
  • Wow
Likes: FastOlson
Jul 27, 2011
5,134
Bavaria 38E Alamitos Bay
No one likes noise.
Even the non-wealthy?:doh: The folks most likely to have FH sounds disturb their sleep are the live-aboards and weekend overnighters at the marinas, being so near ‘em. I always thought the sounds part of the seaside ambiance, like the smell of decaying kelp on the beaches of San Diego County. But the other consideration is that these days with GPS, etc., which nearly everybody has, the boaters usually know where the harbor entrance is, and when they near nearshore. Who needs the FH when you have an arrival alarm? Could be that they just are obsolete like, as others have claimed, paper charts—the printing of which is to cease. But see some of the posts above to get the official reason, at least.
 
Last edited:
  • Like
Likes: Alan Gomes

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,744
CAL 35 Cruiser #21 moored EVERETT WA
The VHF activated sound signal is just like a pilot wanting to land at a remote airport at night. You fly over the dark gound searching for the airport. When you get close you click your radio on the designated signal and if lucky the airport lights turn on. If no lights you check your fuel gauge and then your map and try to figure out what happened.

Guessing now you can do the same on your boat.