Heading Sensor

[Muddy13]

I have just bought a Sadler 29 and would like to install a heading sensor. I've been looking at the simrad/b&g Precision-9. Does anyone have any experience with it? I was planning to mount it below deck near the chart table.

Thanks, Steve.

 

[john_morris_uk]

A compass?

 

[Norman_E]

You only need that if you have an NMEA200 system that needs it for the autopilot, otherwise its just a very expensive compass. In any event a gps either inbuilt into a plotter or separate will give you COG (Course over ground) which is your true (in the sense of not magnetic) heading whichever way the boat is actually pointing. If the Precision 9 is a fluxgate compass it in effect an electonic device that reads a magnetic compass, as such it will need careful positioning. My own boat has a fluxgate compass for its autopilot but there is no reason why an autopilot cannot use COG or bearing to waypoint for control.

EDIT: As an aside a sailing boat in tidal waters still needs you do your own thinking and make allowances for tide in setting a cross tide course to a waypoint. If you leave that up to a simple autopilot it will just keep pointing the boat at the waypoint and end up fighting the tide instead of using it.

 

[Muddy13]

Thanks for the comments. I'm looking to get a B&G Vulcan 7 plotter which has a Sailsteer function for calculating the best tack to get to the next waypoint using tide,heading and wind data - hence the question. The side issue is that the deck compass is broken so the plan was to replace it with a heading device and use a hand-held if the lights went off.. There is a cheaper option (http://www.bandg.com/en-GB/Products/ZG100-GPS/) which is not a great deal more that a replacement deck compass.

Cheers, Steve.

 

[Martin_J]

Check out the Lowrance Point-1... I use it with a couple of B&G Zeus displays.. and it is good enough for chart/radar overlay. Marpa even works quite well with it.. although the spec does say it's not approved for Marpa.

I see it' looks the same as the ZG100... Might be easier/cheaper to find. Lowrance Point-1 or B&G ZG100

 

[Norman_E]

An ordinary magnetic compass that works even if all the electrics fail is something every boat should have. The second device you have linked to is a GPS with NMEA 2000 connection, but if you are buying a Vulcan 7 plotter that has its own internal GPS antenna, you don't need an external one if the plotter is going to be cockpit mounted. Save the cost for something you really need.

If you really want an NMEA2000 antenna, look on e-bay. If you are quick this one can be had for £50! http://www.ebay.co.uk/itm/GARMIN-GP...774230?hash=item25bdb87c56:g:eu4AAOSwubRXH1JP

EDIT: That one has no mount, but you can fit it quite easily under the deck somewhere that has no metal fittings above it.

 

[laika]

You have every right to be irritated if I answer a different question telling you something you already know since I have no experience of the Precision-9 but just in case...

Consider what else you need in your set-up. You'd want a fancy gyro compass for two reasons: MARPA and autopilot. If you don't need either you don't need something that expensive with a fast heading output. As Martin_J said, the B&G ZG100 is also sold with simrad and lowrance stickers slightly cheaper:
http://www.panbo.com/archives/2013/02/navico_new_gpsheading_sensor_vhfgps_handheld.html

These give you GPS as well as magnetic heading, but NOT fast enough to be "approved" for MARPA.

If you don't have an autopilot, or have an old rubbish autopilot you might want to upgrade, think about whether you want one before splashing out on a separate fast heading gyro compass. The right autopilot system for you might come bundled with a heading sensor which will also work for MARPA.

 

[roblpm]

Airmar H2183 on eBay £110

Look at this on eBay http://www.ebay.co.uk/itm/262501493766

 

[roblpm]

And u need a cable too:

Look at this on eBay http://www.ebay.co.uk/itm/252440258947