Fog

[Alaskan Sea-Duction]

Good advice if you are tied up, stay tied up until it is clear. However, if you do any cruising you will NOT be able to avoid fog. You will have to run in it sooner or later.


So its important that you AND YOUR ADMIRAL train using your radar. Run it on a clear day and notice how things appear on the screen. What does a ship look like, a buoy or another recreational boat. What does a rain squall (heavy rain) look like. Change the setting go from 1/2 mile to 1/4 and notice the difference. READ THE MANUAL!


Two reasons to include the Admiral. First, on my boat, she has veto power on all weather related conditions. Second she will be looking at the radar screen and forward through the fog to assist you. She needs to know how to run the radar too. Two sets of eyes are better than one. My Admiral was a little resistant at first, but once she saw how important she is in these situations, she understood the stress with things like fog are on you as the captain.

 

[Eddie]

Good info here folks. Thanks for picking up the fog topic from an older post. That's pretty cool. Btw, the next morning after I originally posted this in Southport, NC, the fog had lifted and we had no issues at all. But, I'm sure we will one day have the opportunity to use this knowledge. Thanks again to you all.

 

[High Wire]

Assumptions:

Velocity (V) = 8kts
1 mile = 5280 ft.
1 Kilometer (km) = 1.15078 statute mile
1 kph = 9.20624 mph

This is messed up!
You are mixing up Nautical MPH with statute MPH and Kilometers per hour.
1 kilometer = 0.63 statute miles
1 kph = 9.20624 mph ( I dont think so! ) Try 0.63 statute miles per hour.
1 nautical mile = 1.15 statute miles = 1.85 kilometers = 6015 feet

 

[twistedtree]

On using radar to help in fog....... try using (M)ARPA if your radar has it. Watching a dot on the radar is one thing, but seeing clearly what direction and speed it’s moving is incredible helpful and stress reducing when you have zero visibility.

 

[Shrew]

This is messed up!
You are mixing up Nautical MPH with statute MPH and Kilometers per hour.
1 kilometer = 0.63 statute miles
1 kph = 9.20624 mph ( I dont think so! ) Try 0.63 statute miles per hour.
1 nautical mile = 1.15 statute miles = 1.85 kilometers = 6015 feet

There are no Kilometers in my equation. I should have clarified my acronyms better.

kph = Knots per hour (Nautical Mile, NOT Kilometer).

The objective is to take a speed in nautical miles and convert to feet per second. Kilometers aren't coming into play.

 

[Shrew]

Assumptions:

Velocity (V) = 8kts
1 mile = 5280 ft.
1 Kilometer (km) = 1.15078 statute mile
1 kph = 9.20624 mph


(5280 * 9.20624) = 48,608.9472 ft/hr

(48,608.9472/60)/60 = 13.5024 Ft/second

8 kph = 13.5024 Ft/second

1/4 mile = 1320 ft

1/4 mile @ 8 kph = 97.760 seconds.

Nope, you're right. I even confused my own acronym. The math is for Nautical MPH, I actually wrote 'kilometer'. I guess I used kph (knot) and my mind made the jump.

The conversion is actually Nautical Mile to Statute mile. However, if you take that weird conversion out and use (1 Nautical Mile = 6076.12 feet.), then numbers are still correct.

((6076.12 * 8)/60)/60 = 13.50248

8 kts = 13.50248 feet/sec

I apologize for the confusion.

 

[BandB]

kph = Knots per hour (Nautical Mile, NOT Kilometer).

The objective is to take a speed in nautical miles and convert to feet per second. .

A knot is one nautical mile per hour so you would never say knots per hour because that would be nautical miles per hour per hour. So there is no kph for knots per hour. Kph is kilometers.

Another one many of us do is refer to RPM's. It's only RPM. RPM already says "revolutions" in the plural.

 

[psneeld]

Understand the concept of constant bearing, decreasing range...... no matter what blob is on your radar, with or without marpa or arpa, really helps.

Anything tracking towards the center is bad, everything else is probably not an issue....unless it turns and tracks inbound.

 

[CaptTom]

IF he is going as fast as you. I've tracked guys going over 20 knots in bad visibility.

Same here. Nine times out of ten it's a 40-foot+ express cruiser, on plane, with no-one visible at the helm.

At that point, I've probably been tracking the other vessel on radar and am well focused and already planning evasive action. Things develop pretty quickly as the CPA approaches.

In that situation I'd rather be going a little faster (for argument's sake, maybe 8 instead of 4 knots) to give myself quicker maneuverability. You may have only moments to get your boat out of the way.

 

[BandB]

ASD mentioned practice. It took me a lot of practice. My wife seemed to have it mastered the first time, identifying everything accurately, just picturing it all so easily. To me it was very abstract at first. I saw dots and blobs, not boats, not markers. Speed was difficult for me to judge too. However, I practiced day and night, I blocked my view and proceeded with radar only while she looked out the windshield. The key is to be prepared when it is all you have and comfortable that you can read and translate.

 

[foggysail]

Same here. Nine times out of ten it's a 40-foot+ express cruiser, on plane, with no-one visible at the helm.

At that point, I've probably been tracking the other vessel on radar and am well focused and already planning evasive action. Things develop pretty quickly as the CPA approaches.

In that situation I'd rather be going a little faster (for argument's sake, maybe 8 instead of 4 knots) to give myself quicker maneuverability. You may have only moments to get your boat out of the way.

Yes, and if there was someone at the helm, he probably would not see you especially if you were close.

I have seen a couple of boats that were ran over by expresses and there currently is a popular video going around the net showing an express doing just that.

 

[psneeld]

My experiences are with smaller 17 to 30 CCs and walkaround fishermen...mainly because they outnumber the bigger expresses 100 to 1....and many dont have radar.

 

[aboatman]

I would say that if you have to ask, you should stay in port. It's often said that a schedule is one of the most dangerous things you can have on a boat. Try to never put yourself in a situation where you feel compelled to travel when conditions are questionable.

In any event, you should never travel so fast that you can't stop in the distance you can see in front of you (same goes for driving a car). If that means three knots, so be it. Track (on your chart or chart plotter) where navigation aids are and make sure you can see them when you get near. Otherwise, you may hit one.

Don't forget to turn on your navigation lights, sound fog signals as required and listen for fog signals from other boats. If you have a typical puny stock horn, get a louder one or one of the VHF radios with built in fog signals (you will need an external speaker as well).

 

[caltexflanc]

My experiences are with smaller 17 to 30 CCs and walkaround fishermen...mainly because they outnumber the bigger expresses 100 to 1....and many dont have radar.

Having big air horns helps. If your boat design safely allows, so does having someone near the bow , watching and listening.

I remember one particularly bad day on Block Island Sound, heading into Buzzard's Bay. Some of the stuff I saw on the radar was hair raising , all the near collisions a few miles from us in open water. It was right before the 4th of July, so all kinds of boaters were out and about. The next day, a Coast Guard cutter collided with a ferry!

 

[OldDan1943]

My experiences are with smaller 17 to 30 CCs and walkaround fishermen...mainly because they outnumber the bigger expresses 100 to 1....and many dont have radar.

Even if they have RADAR, way too many times they do not lower the RADAR beam, once the boat's bow is stuck up in the air.

"I have a big boat, get out of my way!!!"

 

[caltexflanc]

Even if they have RADAR, way too many times they do not lower the RADAR beam, once the boat's bow is stuck up in the air.

"I have a big boat, get out of my way!!!"

That's a poor installation then. Almost all radars on that type of boat are shimmed to be close to level at cruising speed.

 

[markpierce]

Having big air horns helps. If your boat design safely allows, so does having someone near the bow , watching and listening. ...!

Our horn (D-1 Kahlenberg air horn) is too loud for someone on the foredeck. We need to keep the upper half of the pilothouse Dutch doors open to hear others.

 

[psneeld]

not sure the guys screaming along in CCs can even hear air horns...if they can, they are oblivious anyhow....

 

[markpierce]

Thinking maybe I should reduce the automatic fog-horn interval from two minutes to one minute.

 

[caltexflanc]

not sure the guys screaming along in CCs can even hear air horns...if they can, they are oblivious anyhow....

Some do some don't. It doesn't hurt, that's for sure and that's why I said "helps" not "cures".

In our case the person on the foredeck is forewarned of the upcoming blast by the person at the helm so they can cover their ears. Also they stand on the side of the boat away from the horns, which were mounted on the port side about 8 feet above the main deck.

 

[BandB]

In the Video going around of the express running over the fishing boat, it struck me that the fishermen did all this silly waving, but never used a horn. Not saying it would have helped but if they didn't see you, they weren't going to see you waving, and perhaps they might hear you.

 

[tiltrider1]

Running in the fog is a rather common occurance in the PNW. Fortuantley things are wide open and I rarely get closer than 1.5 nm to another boat. For me the big issue is small fiberglass sail boats with no reflectors and kyacks(often I only get random pings form those two). You would be surprised by how many kyacks I have crossed paths with in the fog 5 miles off shore. Even if I'm vigilant 8 to 10 kts is pushing it in the fog, 15-20 and you will run over some one some day.

 

[markpierce]

We rarely operate in fog here. Still, noted two yacht-club-member 35-45-foot sailboats leaving Benicia Marina operating without running lights or sounding horns in visibility of less than a quarter mile in the early dawn. (We were anchored nearby displaying anchor light.)

... How long does a hand-held, canned-air airhorn last, particularly when sailboats under sail need to give multiple signals? Betcha, there is hardly a boat relying on canned air that can sound signals an extended time.

... Since when does a second-or-less blast qualify for a four-second prolonged sound?

... Recreational trawlers moving no more than seven knots are a blessing.

 

[caltexflanc]

Recreational trawlers moving no more than seven knots are a blessing.

Certainly a blessing to those of us trying to pick up radar images!

Speaking of kayaks, once of the Georgia ICW, the only way we sighted a little skiff fishing next to shore in a very tight section, was due to Ann barely hearing the guys talking and then making it out. Even with a well tuned Furuno open array, given the bend in the channel I couldn't distinguish it from the shoreline. Wouldn't have hit but it would have been uncomfortably close. Going 5 knots helped. As we went by we slowed down almost to a stop. One of the guys said good naturedly, "them's horns so loud I'd a thought we was parked on train tracks!" Just then some guy in a bass boat whizzed by at about 30 knots.

 

[Benthic2]

It's a fine line between expanding your comfort zone, and pushing your luck. For people that know what they're doing, Fog is a manageable thing....so how do you become someone who knows that they're doing ? Practice. Get used to running on instruments. On a clear sunny day, Get a competent and capable co-pilot, with full visibility at the helm. You restrict your visibility to the electronics and give him verbal instructions to guide the boat. If you reach your destination, he owes you a beer and a "well done"...if you tell your co-pilot to pull in front of speeding ferry....he fails you, and you owe him a beer. Then go to his boat...and repay the favor.

 

[Alaskan Sea-Duction]

In the Video going around of the express running over the fishing boat, it struck me that the fishermen did all this silly waving, but never used a horn. Not saying it would have helped but if they didn't see you, they weren't going to see you waving, and perhaps they might hear you.

Hell they didn't have time to get the air horn out, let alone use it.......

 

[Mako]

From what I've been reading it seems that the new 4G radars, although marketed mostly to the lower priced recreational market, appear to be exceptional at defining extremely close objects (1/4 mile or less). If so, then if your operations are extensive in foggy harbors/close quarters, this type of unit would be a great complement to a "normal" 4kw-6kw open array.

 

[BandB]

Hell they didn't have time to get the air horn out, let alone use it.......

Then they didn't have a horn in usable location. They sure had time to do a lot of waving of hands before deciding to leap. I know people don't always react logically and applaud them for jumping ship when many would not have been smart enough to have done so. But moving to the bow and waving their arms was not an effective strategy.

 

[Alaskan Sea-Duction]

Then they didn't have a horn in usable location. They sure had time to do a lot of waving of hands before deciding to leap. I know people don't always react logically and applaud them for jumping ship when many would not have been smart enough to have done so. But moving to the bow and waving their arms was not an effective strategy.

Assuming you are correct, would it made a difference?

 

[BandB]

Assuming you are correct, would it made a difference?

I doubt it. Don't know as we don't know the facts of what was going on in the express and neither story told so far makes sense or fully explains it. Just clearly vision wasn't working so perhaps sound would have had a chance.