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Personal PLB V Personal AIS


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#1 Knot Me... maybe

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Posted 16 April 2018 - 02:27 PM

Both are sh*t unless held up high above water inc waves and splashing.

 

Studies coming out are suggesting if you go over and have one strapped to your chest most of the time it will be doing nothing. These units are very prone to being blocked by water, even very little of it.

 

So hold them up high and aim PLB antennas at the sky, AIS antenna at the boat.

 

Stick a silver rescue blanket in your McGyver life jacket. No water issues and will make you more visible to radar, even some quite a long ways away.

 


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#2 Island Time

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Posted 16 April 2018 - 02:47 PM

Show us your references/tests.

Yes, both need their antennas clear of the water. Ais SARTs are limited range, propagated sideways from the antenna, line of sight like all VHF signals. Range is in the vicinity of 4NM, dependent on sea state, antenna height etc - line of sight in a large trough is very short indeed from surface level. PLBs though will still work, their signals go more up, less out.

I reiterate, both need to be clear of the water....

 

A foil blanket might work for an aircraft mounted radar, but, as  with the AIS, at the surface in rough conditions I'd expect its visibility to a radar to be very short distance indeed. 


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There is nothing, absolutely nothing, half so much worth doing, as simply messing about in boats


#3 Fish

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Posted 16 April 2018 - 03:10 PM

I understand foil blankets are excellent for making hats out of.

 

I love reading anecdotal stuff and old wives tails on safety gear. The details and hard facts are too much for my limit attention span.


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#4 Knot Me... maybe

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Posted 16 April 2018 - 04:03 PM

:roll: 


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#5 Willow

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Posted 16 April 2018 - 04:57 PM

Bought a couple of these http://oceansignal.com/products/mob1/ for our shorthanded stuff going to do some testing later in the week, certainly hope they are not useless.

Lifejackets are an expensive piece of kit now with the strobe, AIS and PLB attached.


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Far better is it to dare mighty things, to win glorious triumphs, even though checkered by failure... than to rank with those poor spirits who neither enjoy nor suffer much, because they live in a gray twilight that knows not victory nor defeat.

Theodore Roosevelt

 


#6 Fish

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Posted 16 April 2018 - 05:34 PM

Bought a couple of these http://oceansignal.com/products/mob1/ for our shorthanded stuff going to do some testing later in the week, certainly hope they are not useless.

Lifejackets are an expensive piece of kit now with the strobe, AIS and PLB attached.

KM says they are useless, esp if used in or near water.

He just hasn't posted any links or references so the rest of us are busy making hats out of his foil sheets. We need to wear the foil hats so we can be seen on radar apparently.

 

But other than that, I'm very interested in how they go. How are you going to test them?

I think if they are fitted to your LJ and self activating, and you already have AIS onboard with a chart plotter at the helm (or in the cockpit, visible from the helm), they would be a very useful addition to the safety kit for racing, esp short handed and the at night / coastal / offshore stuff.


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#7 Willow

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Posted 16 April 2018 - 11:15 PM

Yep cockpit mounted chart plotter with AIS, they have a test feature.

One of the UK yachting magazines did a group test of them and reckoned they were worthwhile, range only about 3 miles from memory, they can be setup to trigger a DSC alarm on the vessel and the chart plotter should get an AIS fix pretty quickly so can at least show the last known position.


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Far better is it to dare mighty things, to win glorious triumphs, even though checkered by failure... than to rank with those poor spirits who neither enjoy nor suffer much, because they live in a gray twilight that knows not victory nor defeat.

Theodore Roosevelt

 


#8 Jon

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Posted 17 April 2018 - 08:27 AM

We have ais sart’s for offshore
If we have the ais alarm activated ( turn it off inshore as it keeps going off as I have the cpa set at 1nm ) the chart plotters start screaming their heads off as soon as you activate the sart, which gives you a mob target to aim at, two handed if you go over and activate you sart then if your co skipper doesn’t come back for you then you should have picked your mate better.
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The best sailors do it two handed

#9 Bay Marine Electronics

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Posted Today, 11:36 AM

Hi Guys

We've just got an S20 and Kappa lifejacket in with the intention of doing a test somewhere near the Tauranga harbour. When we have the video done I will post it here so you can see what it's like in relatively flat water.

Just to clarify a couple of things - AIS Sart's should trigger a different alarm to the CPA one - they probably wouldn't be any good if they relied on the CPA as the boat would normally be moving away from the MOB. If I were going offshore, at minimum I would hook up an external buzzer to the alarm output of the chartplotter too - this will make it much louder if trouble were to strike.

And DSC is a completely different system to AIS, however there are a couple of AIS SART's which also have an integrated VHF DSC transmit.


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#10 MarkMT

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Posted Today, 04:14 PM

But Coastguard in NZ have no DSC receiving capability, correct?


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