Do I really need a barometer? Which one?

[RedHerring]

Planning to sail down the West Coast from Vancouver to Cabo this fall.

The barometer I have is dead. Resuscitating it is theoretically possible, but I have enough problems to deal with between now and castoff day. For getting weather forecasts, there is VHF, two SSB receivers and a satellite messenger (Delorme InReach). Is there a scenario where I'd really want to know the local pressure trend?

If so, what should I replace my dead aneroid piece with?

[Paul L]

There's a lot of weather resources available from Vancouver to Cabo . I suspect if you are asking if you really need a barometer then you wouldn't be overly skilled with using one already. You can surely go without one. If you want one then I'd recommend one of the digital recording ones, such as the Nasa unit below

[quill]

My barometer has no batteries. Would not leave shore with out it.

[Dockhead]

Originally Posted by Paul L

There's a lot of weather resources available from Vancouver to Cabo . I suspect if you are asking if you really need a barometer then you wouldn't be overly skilled with using one already. You can surely go without one. If you want one then I'd recommend one of the digital recording ones, such as the Nasa unit below

This.

Mechanical barometers on boats are really for decoration. To get useful information out of them you have to log the readings or at least look often and have a really good memory. Never seen a cruiser do that yet.

A recording one like that one shown is worth its weight in gold. You see the pressure trends at a glance, and its the trend, not the absolute reading (hence the necessity of logging the readings from mechanical ones) which tells the tale. I think every boat should have one.

The one on my boat was inherited from the PO, and is an ordinary weather station. But it also shows moon phases and temperature and is amazingly useful for a fairly banal, household instrument. For people who know even less about weather than I do, the pressure trends are interpreted by the weather station with symbols like rain coming down, sun, partial cloud, etc. which I admit is incredibly useful to give an instant one-glance summary of what is about to happen.

[RedHerring]

Here is the thing. We are talking about ~$300 for what seems like a marginally useful device. I'm sure it's awesome in what it does, but this money could buy something else. E.g., a handheld GPS with charts AND barometer (Garmin 78sc).

Or, just for the heck of it, I can see myself getting something like this, I guess:

LCD Digital LED Torch Altimeter Barometer Compass Thermometer Forecast NEW | eBay

[Paul L]

Originally Posted by RedHerring

Here is the thing. We are talking about ~$300 for what seems like a marginally useful device. I'm sure it's awesome in what it does, but this money could buy something else. E.g., a handheld GPS with charts AND barometer (Garmin 78sc).

Or, just for the heck of it, I can see myself getting something like this, I guess:

LCD Digital LED Torch Altimeter Barometer Compass Thermometer Forecast NEW | eBay

As long as the ,24hr pressure display is readable in that format, it should be fine. The NASA unit is more like usd$200.

[Dockhead]

Originally Posted by RedHerring

Here is the thing. We are talking about ~$300 for what seems like a marginally useful device. I'm sure it's awesome in what it does, but this money could buy something else. E.g., a handheld GPS with charts AND barometer (Garmin 78sc).

Or, just for the heck of it, I can see myself getting something like this, I guess:

LCD Digital LED Torch Altimeter Barometer Compass Thermometer Forecast NEW | eBay

A recording barometer is not at all a "marginally useful device" -- it's fundamental data for any kind of offshore sailing.

But you don't need to spend $250 on the MeteoMan. A $50 weather station will do the job.

[UNCIVILIZED]

Originally Posted by Dockhead

This.

Mechanical barometers on boats are really for decoration. To get useful information out of them you have to log the readings or at least look often and have a really good memory. Never seen a cruiser do that yet.

I'd be one who does exactly that.

A recording one like that one shown is worth its weight in gold. You see the pressure trends at a glance, and its the trend, not the absolute reading (hence the necessity of logging the readings from mechanical ones) which tells the tale. I think every boat should have one.

The one on my boat was inherited from the PO, and is an ordinary weather station. But it also shows moon phases and temperature and is amazingly useful for a fairly banal, household instrument. For people who know even less about weather than I do, the pressure trends are interpreted by the weather station with symbols like rain coming down, sun, partial cloud, etc. which I admit is incredibly useful to give an instant one-glance summary of what is about to happen.

The unit pictured is more of a barograph, than strictly a barometer per say. And likely is more useful. As it records trends in pressure (& other things).

Learning how to forecast the weather, using only basic tools, is as important as learning how to navigate. And I mean navigate for real, sans GPS. Like plotting your position via DR & such, accurately.

With a regular, mechanical, barometer, you, the skipper, decide how often to reset the pin on it. But the watch keeper should be logging the pressure reading every hour, when ship's log entries are made (along with position, course, speed, weather, etc.). And also noting it at any other time entries are made into the log.

Plus, whomever is on watch needs to know when to roust you, when the baro drops by X amount over a set period of time. As such is an indication of weather headed your way.

IMO, 3 baro's isn't too many:
- A barograph/ship's weather station
- A mechanical baro
- A barograph watch (for the skipper)

But the latter two would take precedence in my book.

BTW, there are some really good weather forecasting threads on here, should you be so inclined.

[Dockhead]

Originally Posted by UNCIVILIZED

The unit pictured is more of a barograph, than strictly a barometer per say. And likely is more useful. As it records trends in pressure (& other things).

A barograph is nothing but a recording barometer, so they are barometers per se. Originally they were made by attaching a pen and clockwork paper roller to a barometer drum:



They were incredibly expensive and were prized instruments on board ships.

Originally Posted by UNCIVILIZED

Learning how to forecast the weather, using only basic tools, is as important as learning how to navigate. And I mean navigate for real, sans GPS. Like plotting your position via DR & such, accurately.

I agree, but that will fall on deaf ears around here

Originally Posted by UNCIVILIZED

With a regular, mechanical, barometer, you, the skipper, decide how often to reset the pin on it. But the watch keeper should be logging the pressure reading every hour, when ship's log entries are made (along with position, course, speed, weather, etc.). And also noting it at any other time entries are made into the log.

Plus, whomever

Whoever, not whomever! The English language, like dead reckoning, is an awfully handy skill to have on board, too

Originally Posted by UNCIVILIZED

is on watch needs to know when to roust you, when the baro drops by X amount over a set period of time. As such is an indication of weather headed your way.

Never seen a cruising boat which had hourly baro readings in its log, at least not in my lifetime. Good pratice I guess if you have the manpower for it, but a $50 household weather station makes that unecessary.

Originally Posted by UNCIVILIZED

IMO, 3 baro's isn't too many:
- A barograph/ship's weather station
- A mechanical baro
- A barograph watch (for the skipper)

But the latter two would take precedence in my book. BTW, there are some really good weather forecasting threads on here, should you be so inclined.

A mechanical baro is a great thing to have on board -- as decoration . Sort of like mechanical clocks. I removed and gave away the one which was on my boat; I have a real WWII destroyer's deck clock which I had restored, which fulfills the salty decoration purpose while actually keeping decent time

For real work with baro pressure, there's no substitute for an electronic barograph, and you don't need anything else. As has been mentioned, the key information is the TREND, and in my opinion it is a ridiculous waste of time to log the data from a non-recording barometer.

I have baro data on my network, provided at unnecessarily high precision by the ultrasonic Maretron WSO100 wind transducer on my masthead. You can get a barograph display on most any screen on the boat, and I set network alarms warning of pressure below a certain level (usually 1000mb during periods of good weather) or change of more than several mb per hour.

I pay more attention to this while offshore when I can't get fresh GRIBs off passageweather.com, but I always keep an eye on the weather station next to the nav table -- it's just basic awareness. Funnily enough, the cheap weather station has a much more readable barograph display than the mega expensive Maretron equipment.


I agree with Uncivilized that weather, like real navigation, is a necessary skill for an offshore sailor. I confess that weather, together with scuba diving, is one of the last two major skill sets which I have still not acquired at least a basic mastery of. I can read isobars on a weatherfax chart and understand baro pressure trends, know how fronts work, etc., but there's a lot more to it and I will certainly get to that pretty soon. Meanwhile I use GRIBs from passageweather.com and once you have a certain amount of real life experience interpreting them, these are incredibly accurate, so probably it's tempting to many sailors to never go beyond that for understanding weather, which I think is unfortunate.

[georgelieber]

Buy a used US weather service barometer on eBay. They are super responsive and accurate. Get in the habit of checking it regularly and you will be rewarded with an overall increase of awareness of how the weather is actually changing around you.

[wsmurdoch]

A recording barometer also gives you bragging rights

I'm cheap and let the barograph drum record more than one week's data, so two Saturdays are shown on the chart, 8/20 and 8/27.

[Snowpetrel]

My phone has a barometer sensor. I run a free barograph app. This plus writing the barometer value down in the log at the end of each watch works well


Sent from my SM-G930F using Cruisers Sailing Forum mobile app

[Mike OReilly]

I've used a handheld recording barometer for years (Kestrel). It records and graphs weather data for two weeks (I think... have to check). Temp, humidity, pressure, etc. Great for monitoring pressure trends.

We also have a shippy bulkhead barometer. I set the mark every morning, but our log does have a column for barometer reading. It does get recorded with every entry. Easy to see a trend that way.

[omc]

I have VION A4000 recording barometer since years , very happy with it. There is an alarm for air pressure variation which is very convenient.
BalticProducts | Vion Instruments marine barometer A4000.2

[S/V Alchemy]

I have a 24 hour recording barometer I picked up for $35 10 years ago...I consult it frequently. I also have two "wrist-tops" from Suunto that do the same thing, as well as give me an audible "storm warning" in the case of rapid pressure drops.