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twelve · 22-01-2017, 15:59

Anchor alarms galore–based upon position or depth–but I don’t know of a system that provides for a warning when the boat’s heading changes beyond a preset value. For wind and/or current shifts, a heading alarm may work best. Anyone know of a system that has this feature, or better yet, has anyone had experience with it? Thanks in advance.

**Paul Elliott** · 22-01-2017, 16:03

There are some free computer programs that can do this. NavMonPc does (I wrote this), and I think this is available on OpenCPN. There are of course programs you can buy with this capability as well.

ranger58sb · 23-01-2017, 04:57

Quote:

Originally Posted by twelve

Anchor alarms galore–based upon position or depth–but I don’t know of a system that provides for a warning when the boat’s heading changes beyond a preset value. For wind and/or current shifts, a heading alarm may work best. Anyone know of a system that has this feature, or better yet, has anyone had experience with it? Thanks in advance.

Our autopilot alarms when we're off-track, if we've been overpowered by either wind or current. Ours is a Furuno NavPilot 511, but I'd have thought most APs have this feature?

-Chris

rwidman · 23-01-2017, 06:00

My Garmin 5208 has such an alarm. I don't use it but it's available.

MarkJ · 23-01-2017, 07:25

Off course alarm may be better as a boat at sea may slew off 30 or 40 degrees coming down a wave.

alctel · 23-01-2017, 07:32

Quote:

Originally Posted by twelve

Anchor alarms galore–based upon position or depth–but I don’t know of a system that provides for a warning when the boat’s heading changes beyond a preset value. For wind and/or current shifts, a heading alarm may work best. Anyone know of a system that has this feature, or better yet, has anyone had experience with it? Thanks in advance.

My simrad NSS8 has this alarm and others (wind shift, off course etc). I don't tend to use it as where i am, the wind tends to be pretty squirrelly

twelve · 23-01-2017, 09:58

Thanks all for responses. I am interested in a heading alarm which can be used at anchor. Course alarms–which have usefulness while underway but not at anchor–are quite different. Chart plotters are generally only concerned with a boat’s course, and as far as I know, don’t have heading alarms. (Paul, I rechecked OpenCPN, and if it’s there, I can’t find it). Autopilots which steer a compass course might have audible alarms, but to leave one on at anchor overnight would likely require mechanical disengagement and/or significant power usage. My autopilot does not have an alarm feature.

But NavMonPC, clearly provides what I’m interested in. Thanks Paul, much appreciation for sharing your program. I am using Windows 10, and the program appears to run, but I’ve not yet figured out how to get data in. I don’t see a capability in the program for input from a wifi source–which I can do fairly easily for NMEA 183. Am I reading things wrong, or is there a solution? In the past on older machines I’ve used USB/serial port wired devices for NMEA 183, but the result has been less than reliable.

**Paul Elliott** · 23-01-2017, 11:05

Twelve, NavMonPc can connect to a WiFi (or any network) source that provides a NMEA0183 on TCP/IP server. NavMon does not handle UDP. You will need an IP address and port number for the WiFi server. What do you have now as your WiFi source?

NavMon doesn't do anything specific regarding WiFi, and treats this the same as a wired ethernet port -- your computer will need to connect to the WiFi server and then NavMon can connect to the IP address and Port #.

I realize that this is getting complicated, but if there is incompatibility, there are programs that can bridge the protocol / connection gap. OpenCPN has pretty flexible networking tools, and can also create a local TCP/IP port that NavMonPc can connect to.

conachair · 24-01-2017, 00:45

Quote:

Originally Posted by twelve

[SIZE=4]..... For wind and/or current shifts, a heading alarm may work best.....

Not so sure about that....

The android anchor pro app I use, plus opencpn watchdog allow you to create an area as opposed to a radius so if the boat leaves that area the alarm sounds.
So if the boat veers about a bit in a breeze the alarms doesn't sound, as it would with a heading alarm - but if the boat leaves the cone set between you and the anchor it will sound. Better option IMHO. The opencpn is option is very adaptable with inclusion and exclusion options.

UNCIVILIZED · 24-01-2017, 01:23

If you're wanting something to tell you when things go sideways when at anchor, literally or figuratively, why not just use an anchor alarm? And if needed, set it's radius a bit smaller than usual.

Also, please look into using a smaller font size.

twelve · 24-01-2017, 13:24

Paul, thanks for the help. I’m a bit network challenged and just wasn’t thinking the way you suggested. My system includes a Vesper XB8000 and OpenCPN on a Win 10 computer, and your program is now working fine. I hope to give the heading alarm a tryout in the next couple of months. Thanks again for your help.

Those who, I guess, don’t know what I’m thinking, imagine this:

You’re at anchor, it’s 2200 and time to retire. The wind is so light that the rode is slack, but the boat is pointing southeast into the light surface current. The forecast is for a strong cold front to pass through within 12 hours, bringing north winds of 20+ knots. Your anchor is set with a long rode for those conditions, but often as a front arrives the wind clocks through almost the whole compass. Would you set an alarm? When do you want to be awakened and what type of alarm will do that?

Or this: It’s 1200, you’ve just arrived, and now calmly anchored in a 150 foot wide cut between barrier islands with the ocean in sight. There’s a 2 knot tidal current and other boats close by, some with two anchors. You’re necessarily on a short rode, a single anchor, and sitting pretty–at least for now. It will be 4 to 6 hours before the boat does a 180. You and the crew would like to get as much rest as possible before heading out for a night passage. Do you set the second anchor, an alarm clock for 4 hours, or a heading alarm?

The first scenario is very common during winter in the Gulf of Mexico, Florida, and the Bahamas. The second is a year round occurrence in that area. I suspect other cruising grounds have similar or other scenarios where you'd like to be alerted to anticipated changing conditions. Anchor alarms should not just be for the unexpected. I’d like to know if a heading alarm will do the job.

Uncivilizied, the font on my previous posts was the default. I've reduced it for this one. I did not even notice the size difference from the responses. I only wish I had your vision.

**JPA Cate** · 24-01-2017, 15:24

Hi, twelve,

If you don't automatically wake up from the change of motion when the 20 kn. change comes, and the motion changes, you're a far better sleeper than I am! (PLease, no offense intended.)

Seriously, for both situations, our [Vesper Marine] AIS's anchor watch function works. If you go outside the swinging radius you set, no worries, it shouts at us. However, for planned night time departures, we would set an alarm to wake us with time for a cuppa, and to dress, prior to getting the hook up.

Our AP does have an off course alarm, but it really is for when you're moving through the water on a specific course, not the right tool for an anchor watch.

Ann

conachair · 25-01-2017, 00:53

Quote:

Originally Posted by twelve

You’re at anchor, it’s 2200 and time to retire. The wind is so light that the rode is slack, but the boat is pointing southeast into the light surface current. The forecast is for a strong cold front to pass through within 12 hours, bringing north winds of 20+ knots. Your anchor is set with a long rode for those conditions, but often as a front arrives the wind clocks through almost the whole compass. Would you set an alarm? When do you want to be awakened and what type of alarm will do that?

Or this: It’s 1200, you’ve just arrived, and now calmly anchored in a 150 foot wide cut between barrier islands with the ocean in sight. There’s a 2 knot tidal current and other boats close by, some with two anchors. You’re necessarily on a short rode, a single anchor, and sitting pretty–at least for now. It will be 4 to 6 hours before the boat does a 180. You and the crew would like to get as much rest as possible before heading out for a night passage. Do you set the second anchor, an alarm clock for 4 hours, or a heading alarm?

Both cases a boundary alarm would be a better choice imho, opencpn does this very well, quickly created example below. With even a light puff of breeze over a weak current your boat could be pointing any direction. It's not what direction the boat is pointing that's important but where the boat actually is.

**JPA Cate** · 25-01-2017, 01:58

Mate, I haven't been where he is, but have faced similar situations. That boundary zone is lovely, and if you have the electricity to spare to run the computer all night, with the screen on, good on you.

We have relied so far on the AIS anchor alarm, which has served us well so far.

Ann