Installing Cat II epirb near a compass?

[foojin]

Recently purchased an ACR Global Fix V4 Epirb. Category II.

Quick Start Guide that came with it states the epirb should be placed 1.4 metres from a compass.

Understand how a Category I unit, with a magnetic release switch, would be need to be installed away from a compass. But mystified why a Cat II device, with manual release, must also be placed a distance from a compass.

Is there something in an epirb that would affect operation of the compass. Or maybe it’s a mistake in the QS Guide which also covers the Cat I version of the same model.

Any ideas?

Thanks

[Wotname]

If the EPIRB uses any ferrous metal (and/or ferrite beads etc) in it's construction, then it has the potential to cause compass interference. It isn't just the release mechanism.

[Paul L]

If you feel you really want to install it near the steering compass, then while tied to a dock take the Eprib and place it very close to the compass and see if the compass card moves at all.

[foojin]

Of course you’re right. I was thinking about it only one way. Will test it for interference.

[GordMay]

Test it on several (known) headings.

[Paul L]

Originally Posted by GordMay

Test it on several (known) headings.

If it is a binnacle style compass it would be easier to just move the eprib around the compass to test for changes.

[Cadence]

When all else fails read the manual. If it specifies that distance stick with that.

[foojin]

Yes, it is the device affecting the compass, not the bracket, and not the compass affecting the epirb. Only had to move the epirb around to confirm that.

The compass is bulkhead mounted. New epirb moved it about 20 degrees close up, five degrees where I hoped to mount it.

Interesting, our old epirb, another ACR Global Fix, moves the compass only five degrees close up, but not at all where it was installed (the same place I hoped to install the new one). Though perhaps that would change on different bearings as I think Gord's post suggests.