AIS vs Radar Reflector vs both ??? - Page 2

Observer · 26 October 2009, 11:31

Quote:

Originally Posted by chewy

I'd just use an Echomax radar reflector, if you lose power a See-me one won't work. There's a reason the RNLI changed to Echomax reflectors.

Yes but a leisure RIB is unlikely to choose to go out in the conditions in which an RNLI RIB is required to go out. The chances of losing all electrical power are, I would think, almost negligible in ordinary conditions.

Further, I'm sceptical whether any practical size of passive reflector will actually give a good return mounted on a RIB at (what) 1-1.5m above sea level, at best. The Qinetiq report on radar reflectors was not reassuring in that regard and the Echomax tested has some poor results at larger elevations.

I wonder how well even the Sea-Me (the best performer by a long way) would work at typical RIB height.

Poly · 26 October 2009, 11:34

Quote:

Originally Posted by Observer

Yes but a leisure RIB is unlikely to choose to go out in the conditions in which an RNLI RIB is required to go out. The chances of losing all electrical power are, I would think, almost negligible in ordinary conditions.

Further, I'm sceptical whether any practical size of passive reflector will actually give a good return mounted on a RIB at (what) 1-1.5m above sea level, at best. The Qinetiq report on radar reflectors was not reassuring in that regard and the Echomax tested has some poor results at larger elevations.

I wonder how well even the Sea-Me (the best performer by a long way) would work at typical RIB height.

Recent PBO (or similar) article/trial suggested pretty well actually... although essentially its line of sight so if the waves mean you can't actually see the ship don't expect miracles!

Knot Yet · 26 October 2009, 11:46

Well I think I've decided - will get an AIS Engine 2 - for £100 is seems a good add on for the existing system

From the trials I've read the Echomax Active X appears to be just better the See.Me - £420 at Marine Superstore

Whilst I have no intention of going out in bad weather, fog or indeed breaking down - as we play in the Solent and I have my 14 year old son aboard I'd rather spend my hard earnt money on doing all I can to be prepared than not - at least this way I call call up passing traffic and know I've done all I can to make my footprint as big as possible - I know it's not perfect and perhaps too OTT for most - anyway when I get my "Super Yacht" - I can always transfer it

Thanks all really do appreciate all the help given

J

wavelength · 27 October 2009, 17:57

which Ais do you intend to get, is it waterproof and will it interface with your plotter? Just interested as it could be good for me too if you have found sommat suitable for a rib at a reasonable price.

Knot Yet · 27 October 2009, 18:32

Hi Dave

It is an AIS Engine 2

http://www.marine-super-store.com/po...artno=99119713

We did get a bit of discount so only £100 - we will fit it inside the console as it should'nt get wet and it does interface (with some wiring magic) to the GPSMAP 550s

Will let you know how the fitting goes

J

chewy · 27 October 2009, 19:10

Quote:

Originally Posted by Observer

Yes but a leisure RIB is unlikely to choose to go out in the conditions in which an RNLI RIB is required to go out. The chances of losing all electrical power are, I would think, almost negligible in ordinary conditions.

I don't think the RNLI stopped using them because the Atlantics lost power at night, more to do with how do you know when it is and isn't working. I know it comes with a unit to show when its been interrogated but I'd rather have a unit that works less well all the time than a unit that may fail when I need it most.

wavelength · 27 October 2009, 19:16

I had enquired with my supplier about which ais engines he did and that was one of the two. His opinion was not waterproof as we know but also "not suitable for an open boat even in a consol although some folk have fabricated their own waterproof box but be aware of any heat issues" Be interesting to see how it goes.

jwalker · 27 October 2009, 19:20

Quote:

Originally Posted by chewy

....I know it comes with a unit to show when its been interrogated but I'd rather have a unit that works less well all the time than a unit that may fail when I need it most.

Hehe, reminds me of the old fuddydudy arguments when cameras changed from manual to auto exposure - wot'll happen if the battery runs out... now look where we are!

wavelength · 27 October 2009, 19:23

Quote:

now look where we are

with flat batteries usually ?????

jwalker · 27 October 2009, 19:29

Quote:

Originally Posted by wavelength

I had enquired with my supplier about which ais engines he did and that was one of the two. His opinion was not waterproof as we know but also "not suitable for an open boat even in a consol although some folk have fabricated their own waterproof box but be aware of any heat issues" Be interesting to see how it goes.

I have the earlier version. It's in a cabin but it works very well interfaced with my Garmin plotter so if you keep it dry I suspect it'll be fine. Mine unit doesn't have an on/off switch, it's connected to the ignition so comes on with boat power.

jwalker · 27 October 2009, 19:30

Quote:

Originally Posted by wavelength

with flat batteries usually ?????

Not me. Fierd o the day yer never saw! hehe..

Spose that's my argument fried, then..

Poly · 27 October 2009, 19:40

Quote:

Originally Posted by chewy

I don't think the RNLI stopped using them because the Atlantics lost power at night, more to do with how do you know when it is and isn't working. I know it comes with a unit to show when its been interrogated but I'd rather have a unit that works less well all the time than a unit that may fail when I need it most.

But is there a known problem? If a tiny number of units actually spontaneously fail in the field then I'd rather have the more effective system, and accept that there is a very small chance it will fail, and that I may not be aware it has failed, and that Radar recognition by the third party would be "critical" to the activity I was undertaking at the time - than have a system which is effectively "failing" some of the time on every trip.

Why not have both if you are that concerned and have RNLI budgets?

jwalker · 27 October 2009, 19:47

The Sea-me has a monitor LED which indicates it's in action. It is triggered by the increased current used for retransmission of the received radar pulse so if the LED lights, the unit is transmitting.

Knot Yet · 27 October 2009, 19:52

Interesting re the heat issue on the AIS engine - we were going to place it inside the console in a fabricated waterproof box - so doubley protected - might have to rethink if heat is a concern

J

wavelength · 27 October 2009, 20:03

cant think there would be that much heat. NASA gear has always been cheap and cheerful but if it works cheap is good! Interesting when their ais came out I made enquiries re getting hold of one for a magazine test but got a short reply to say it wasnt waterproof and a rib was the wettest boat they knew.

jwalker · 27 October 2009, 20:16

Quote:

Originally Posted by Knot Yet

Interesting re the heat issue on the AIS engine - we were going to place it inside the console in a fabricated waterproof box - so doubley protected - might have to rethink if heat is a concern

J

Heat isn't an issue. It draws a few milliamps, how much heat can you make with that!?

Knot Yet · 27 October 2009, 20:24

Okay excellent - so it was just the supplier who was concerned with possible heat issues

Quote:

His opinion was not waterproof as we know but also "not suitable for an open boat even in a consol although some folk have fabricated their own waterproof box but be aware of any heat issues"

Will continue with the mission of finding a suitable waterproof box

J