Anyone use a gps tracker or similar to monitor your boat for anchor drag when unattended?
Wokos right 
Theres an Australian made device called Trek Transponder that monitors anchor drag. (And bilge, batteries etc). If your boat drags past your set radius you get an SMS alarm on your phone if you are onshore and a really loud beeping if you are on board. Nearly 1000 units around Australia now.
Select to expand quoteduncansayers said..
The Anchor Pro app can do remote alerting to a second phone.
I think I'll go and buy an el cheapo phone tomorrow for the stay-on-board phone so I can get something happening straight away
Select to expand quotebullrout said..duncansayers said..
The Anchor Pro app can do remote alerting to a second phone.
I think I'll go and buy an el cheapo phone tomorrow for the stay-on-board phone so I can get something happening straight away
Needs to see the sky though doesn't it? Maybe tape it underneath a hatch.
They do bur usually can get enough signal most places on board, unless its a metal boat.. You can do the test with a mobile phone that has a real GPS not a WiFi GPS.
If you put the phone where the unit you choose will be mounted and it reads your location ok then the device should work too. Trek Transponder has a much larger better antenna with an amplifier in it when compared to a phone, or for a metal boat an extenal antenna with an amplifier in it, because the location delays you sometimes see on a phone are not good on a boat. Also because it provides an accurate NMEA 0183 output for the free OpenCPN chart plotter.
Select to expand quotejulesmoto said..bullrout said..duncansayers said..
The Anchor Pro app can do remote alerting to a second phone.
I think I'll go and buy an el cheapo phone tomorrow for the stay-on-board phone so I can get something happening straight away
Needs to see the sky though doesn't it? Maybe tape it underneath a hatch.
I've used Anchor Pro with my phone sitting on charge inside the cabin of my boat while I sleep. Works fine.
Select to expand quoteduncansayers said..julesmoto said..bullrout said..duncansayers said..
The Anchor Pro app can do remote alerting to a second phone.
I think I'll go and buy an el cheapo phone tomorrow for the stay-on-board phone so I can get something happening straight away
Needs to see the sky though doesn't it? Maybe tape it underneath a hatch.
I've used Anchor Pro with my phone sitting on charge inside the cabin of my boat while I sleep. Works fine.
I thought GPS antennae require line of sight to sky. I'm assuming the phone is using triangulation of 4g signals if the sky is not visible. Anyone want to correct me as I could be wrong?
Select to expand quotejulesmoto said..
I thought GPS antennae require line of sight to sky. I'm assuming the phone is using triangulation of 4g signals if the sky is not visible. Anyone want to correct me as I could be wrong?
I use the Anchor Pro app off an iPad sitting at the nav table. On a 6 month sail from Brisbane to Perth we mostly had some mobile coverage and I became reasonably confident in its tracking. We spent 4 weeks in the Kimberlys 3 of which had zero mobile coverage and I don't believe the apps performance was degraded. One day at home, I used the same iPad with same anchor app on and put it on my bed for a few hours. I was amused at the amount of movement. I have a tin roof, and although my bed is close to 2 glass doors to the outside, there is a few metres of tin roofed veranda.
GPS signals for what they do are extremely weak, but I think it is the structure they are under that makes more of a difference.
Oh, and when I say I became 'confident' with its tracking, it generally took at least a day before I was
I have an old bad elf gps plugged into an even older iPad and it works in the saloon with a steel cabin top, when I turn it on, if it's slow to find enough satellites to operate I take it on deck, when it fires up it it's fine to take below
Select to expand quotejulesmoto said..duncansayers said..julesmoto said..bullrout said..duncansayers said..
The Anchor Pro app can do remote alerting to a second phone.
I think I'll go and buy an el cheapo phone tomorrow for the stay-on-board phone so I can get something happening straight away
Needs to see the sky though doesn't it? Maybe tape it underneath a hatch.
I've used Anchor Pro with my phone sitting on charge inside the cabin of my boat while I sleep. Works fine.
I thought GPS antennae require line of sight to sky. I'm assuming the phone is using triangulation of 4g signals if the sky is not visible. Anyone want to correct me as I could be wrong?
I have a trek mounted inside a cupboard in the head, totally enclosed, works fine. 
Select to expand quotejulesmoto said..
I thought GPS antennae require line of sight to sky. I'm assuming the phone is using triangulation of 4g signals if the sky is not visible. Anyone want to correct me as I could be wrong?
GPS sends a radio signal with timing data. It uses this timing data to triangulate your location based on the time the signals from the satellites take to reach your GPS receiver. Some material (metal roof etc) will block the signal and you don't get a location fix. Other materials, like the ply epoxy roof of my boat will slightly slow the signal down causing some inaccuracy. A clear line of sight to the satellites will give the most accurate location result.
OP - you said "anchored" - did you mean "anchored" as in "moored in its usual location" or literally anchored which kind of implies anywhere - including places with no coverage?
JonE, he actually said "for anchor drag", which would imply to me that they are referring to using the anchor and not a mooring.
Select to expand quoteJonE said..
OP - you said "anchored" - did you mean "anchored" as in "moored in its usual location" or literally anchored which kind of implies anywhere - including places with no coverage?
Yes anchored when I'm at work, I was thinking of something like a map on my phone I can bring it up anytime and see the boats position, alarm would be a bonus
Select to expand quotebullrout said..JonE said..
OP - you said "anchored" - did you mean "anchored" as in "moored in its usual location" or literally anchored which kind of implies anywhere - including places with no coverage?
Yes anchored when I'm at work, I was thinking of something like a map on my phone I can bring it up anytime and see the boats position, alarm would be a bonus
That's what the eBay trackers linked to above do. Just pick one with the features you want. Hooked up direct to your 12v battery they would be ideal for monitoring the mooring security during the upcoming Westerly gales.
