Raymarine Life Tag

[Ian_Edwards]

Hi,
I'm thinking of adding a Life Tag system to my existing Raymarine kit, which consists of E80 MFD, ST6002+ autopilot, S2 core pack with gyro, ST60, wind, depth, speed and a radar system.
I can see how the Life Tag will display a MOB position on the E80, but will it interface with the autopilot system?
Could I make the boat turn "head to wind" if I'm sailing single or shorthanded?
I can't see anything on the Raymarine site that helps and I've searched the Forum and Google for "Life Tag" and variations on that theme, with no useful results.
Has anyone out there tried to install a Life Tag and interface it to an E series and autopilot?

 

[saltwater_gypsy]

I have LifeTag interfaced to a C120 and it seeems to work OK. I don't see anything about interfacing to an autopilot but what you suggest is a really good idea.
I think that you could use the relay facility to DISCONNECT the autopilot if your boat tends to head up naturally.

 

[Ian_Edwards]

Yes, I've been thinking about how you could use the Life Tag system to do "something sensible", but it depends on what the boat is doing at the time the MOB happens and whether your single handed or not. Steering back to the MOB waypoint sound obvious at first, but if we're motoring at 8knots, I'm not sure I want 8 tonnes of boat bearing down on someone (let alone me!) at that speed. Putting the boat head to wind might work under sail, cutting the engine might work under power (possible with a solenoid driven stop), but if there is crew on board, you’d have to be able to restart the engine, reliable and easily.
What I’m really looking for is some way stopping the boat to improve my chances of catching it up, or not getting towed along if I’m clipped on. And yes, I know all about clipping on, which we do when the conditions obviously warrant it.
What do other think?

 

[temptress]

We have a life-tag system installed onboard and in the main ship-based unit there are connections for an external ‘alarm’ or speaker which gets activated when a MOB is detected. Also the system puts a message MOB on the SeatalkBUS so this could be used. This gets relayed to NEMA if you have a NEMA/SeaTalk interface box

I may be wrong but I don’t think there is anything commercially available to do what you need.

You could use the MOB external speaker signal as a trigger to do whatever you need. For example a it could operate a relay switch that disconnects your autopilot. Components to wire this up are available off the shelf from the likes of Maplin or RS components.

Alternatively you could pick up the seatalk message, interface this with a laptop and write a programme to do whatever you need but probably beyond the ability of most on here.

Good luck
/forums/images/graemlins/smirk.gif

 

[rogerthebodger]

I saw that design of a system like this some time ago but cannot find the article at the moment and this was before the life-tag type systems were around.

It consisted of a switch that would determine which tack the boat was on and then switch a relay that was connected across the remote control of the autopilot to put the helm hard over to the correct direction. It would also start a delay off timer that would shut the engine down (operate the stop solenoid) for a short time until the engine had stopped and then open which would allow the engine to be restarted again.

NASA will be supplying a MOB unit like the life-tag but at a lower cost which includes a contact that closes when MOB signal is lost so could be used to operate a system as described above.

I plan to do this on my new boat once I get it into the water later this year

 

[William_H]

If you are using a harness. It should be so short as to not permit you to go overboard.
If however you use a long tether you will have no chance of doing anything yourself if being dragged along at even a moderate speed. The drag however will be huge such that you may be able to devise a system to use the drag on the deck attachment lines to pull the rudder to hard over. Perhaps overcoming a kind of weak link connecting a/p to tiller.Perhaps even to the throttle or stop lever. Once the tiller is hard over the boat will inevitably come to a stop if sailing or at least reduce the pull on your harness if motoring.
But best to not go over by short tether at all times.
just a few thoughts olewill