Raytheon and other systems

[Guest]

Following on from my last post I was wondering on peoples views on the above.

Rather than rush head long into buying the full kit, chart plotter, gps, autopilot etc I feel I would be better served getting basics first but making sure it is an expandible system that should not give me any headach's when installing the next bit of kit.

I have the Raytheon brochure in front of me and one of trheir suggested layouts is Raychart 320 - ST40 Bidata & Wind - Autopilot ST2000+ & Satelite Differential GPS.

Does anyone at present use this or another configuration and for starters what are the merits to say starting with the Autopilot and gps then expanding from there as I become more adventuerous.

 

[philip_stevens]

Tim,
I started out with an Autohelm 2000. This only spoke in Seatalk. I could sail by Autohelm fluxgate compass.
I then obtained a GPS. This spoke in NMEA. I could navigate by GPS.
To get the GPS to be able to talk to the Autohelm, I bought an Autohelm Interface box. So now the GPS can talk to the Autohelm and I can sail by GPS instructions as well as by Autohelm fluxgate compass.
Last winter I bought Navman (from Plastimo distributors) Speed, Wind and Depth. The speed talks to the wind, and I can get apparent or true wind speed and direction. All the instruments talk to the GPS, so it can display all from the instrumens.
The GPS can also talk to the Autohelm, and it can now steer by wind direction if I so desire.

Information from the GPS and information it gets from the instruments, can also be sent to a Radar or Plotter if you fit them.

So, to make life easy to start with, you could get an Autohelm or GPS or both. Then you could get the nav instruments. All can talk to eachother. Whichever order you buy them in, make sure they have an NMEA output. So long as they do, you don't have to buy the same make of equipment.

NASA instruments do NOT have NMEA output. Raytheon and the Navman series (that I have) do have NMEA output.

This is my view, and there will be others - some agreeing, and some disagreeing. We are all different.

regards,
Philip

 

[Guest]

Thanks for that,

looks like I need to take a crash coure in seatalk and NMEA, (just found one interesting site http://zazu.optiva.ee/pub/nmea/)

Not a language/protocol I have had to deal with yet, although have looked a bolting gps into a mobile.

 

[yachtbits]

only comments I would add is not to bother paying the extra for a Differential GPS. A decent non-diff gps will give +/- 15mtrs or better now selective availability is off.

Silva do a good range of networked instuments Nexus range. worth a look and sensible prices, nmea output and data displayed on multiple displays.

kev

www.yachtbits.co.uk
sales@yachtbits.co.uk
marine electrical/electronics specialists

 

[billmacfarlane]

I wouldn't bother with the differential GPS as with selective availability turned off , most GPS sets have excellent accuracy. If you buy all Raymarine who have their own Seatalk interface , as somebody already said , you'll need an interface box to use non Raymarine instruments e.g you might decide to buy a Garmin GPS set , though it might be worth seeing if Raymarine do a purely NMEA version of the kit you want to buy.

 

[Twister_Ken]

My suggestion for prorities would be:

1. Compass (magnetic)
2. Depth (unless you plan to sail in very deep waters)
3. Speed and distance through water
4. GPS
5. Wind speed and direction, inc close hauled and trim functions
6. Auto pilot
7. Compass (fluxgate)
8. Chartplotter

I think items 2 and 3 can be combined in a bidata type unit.

Buying all the instruments (over time) from one manufacturer should ensure not only compatability, but also ease of connecting them together.

GPS and Chartplotter could be combined in one unit, but a spare handheld GPS is always very good insurance against failure of the main instrument.

Autopilot is an interesting question. If you're newish to sailing you're probably going to want to spend much of the time with your hand on the helm, and also you probably won't be doing long passages for a while. Why not buy a cheap (relative term!) standalone autopilot, which doesn't need to be plumbed in to form part of a totally integrated system. If you do want to upgrade it later, then you've got a spare autpilot. If you read cruising logs, the autopilot always seems to break down at some point!

I'm a bit dubious about chartplotters, not in principle, but because the software costs (chart packs) seem very expensive, and difficult to update. Even with the world's best chartplotter aboard, you should carry the relevant paper charts, so why not start with the paper, and see whether you want to graduate to a chartplotter later. I do question the importance of knowing exactly where you are at all times. To take a southcoast example, it's enough to know you are somewhere more or less on a straight line between nab Tower and Cherbourg for most of the time. Only when you're getting close to either side soes it become important to know where you are more accurately, and you can either do that by traditional methods like taking sights and or using depths (which are skills you should acquire anyway, against the day the machines go pop), or from a GPS.

Incidentally, for plotters, don't forget the Yeoman system which makes use of paper charts rather than software ones.

Hope it helps.

 

[HaraldS]

Happens that I have a mix of NMEA and SeaTalk on my boat and as an electronics engineer I have also investgated things quite deeply. Here just a few important things to that topic:
SeaTalk is a bus, which means you can connect multiple senders and receivers to the same wire. This makes it very convenient to interconnect. Conflicts of multiple devices trying to talk at the same time are automatically resolved, first by listening carefully if somebody already talkes and when talking checking your own talk, whether it's garbled by somebody else talking at the same time. In that case the talkers stop and retry at a random interval. The net result for you is a very simply wireing.
NMEA allows for just one sender on a wire. It's possible to have multiple listeners on the same wire. If you need to combine multiple NMEA outputs, you will need a special device, often called a NEMA bridge or multiplexer.
Not everything may work as expected when you connect NMEA and SeaTalk. The Raymarine bridge is 'intelligent' and builds different SeaTalk sentences from different NMEA sentecnces and vice versa and not all information may be propagated.
An example is the NMEA RMC-sentence which is sent out by most GPS's, it contains UTC, LAT, LON, GPS quality, and local magnetic variation. If you bridge this to an SeaTalk based flux-gate compass or autopilot containing one, you will notice that variation isn't passed on, and you would have to set it yourself if you want a true reading.
In general I'd say you get about 95% of what you would expect when connecting the two systems.

With respect to the differential GPS, I agree with the folks who said it isn't really worth it, after SA had been switched off. Also, it would only work in certain areas. I you want to spend extra money for increased accuracy, look for a device that does WAAS. This is quite similar to D-GPS, but the correction signal comes per sattelite, hence will be available globally.

 

[charles_reed]

Now that's an interesting priorisation, Twister_Ken, mine would be quite different

1. Magnetic compass
2. Radar
3. Autopilot
4. Echosounder - transpose with next if if deep-water sailing
4. GPS
5. Log
6. Electronic chartplotter (not your Yeoman compromise)
7. Windvane steering
8. Navtex
9. Wind-indicator and anenometer

Here are my reasons

Radar gives one distance off, very accurately, and bearing, not so accurately.
As a singlehander, the autopilot is and essential, and as ex-dinghy sailor wind indication is pretty redundant, telltales are far better.
Having just invested £32 in two Admiralty charts for routing - I really couldn't afford the cost or storage requirements for a full set (Western Approaches and Med).
But then one doesn't know what one doesn't know.

In reply to the original post, I'd connect up using NMEA 083, even at 2400 baud it's as fast as Seatalk - I have a reluctance to commit to any closed architecture, you're tied into that system; except for autopilots Raytheon do not offer either the best technically or the best priced marine instruments in any other category.
Incidentally you can connect Raytheon instruments on NMEA 083.

 

[Twister_Ken]

Charles - a bit of expansion on my reasons.

No radar - our man TimE is buying a 25ft trailer/sailer. Radar might be a bit OTT.

Echo sounder at no 2. Well it's probably the instrument I look at most often sailing on the South coast, but you've got to have a compass at number 1. OTOH, I remember sailing so close to a headland on the West Coast of Scotland, that I could have spat on it, and the echosounder was off the scale at 100 foot plus.

Speed and distance through water - everybody want to know how fast they are going, and whether they can make it go any faster, and only a log does this. GPS gives SOG, which can be very different, but no less useful. And distance is one of the primary DR inputs, useful ordinarily, but doubly so if the electronics go belly up.

GPS - not quite a must have but almost. Mine is usually turned on (it feeds the DSC VHF) but not looked at. When I do use it it is more often not for position, but for hard stuff like working out cross tide headings, spotting the turn of tide, putting a guard zone around hazards, or anchor watch.

Wind speed - I'm with you on this not being an essential, but I think they are very useful for optimising perfomance. If you know that on a certain point of sailing, at a certain windspeed, you can do x knots, then if you're not going that fast you're prompted to sort out sail trim, quick. Also closehauled indication- extremely useful beating at night, when you can't see the tell tales, and don't want a crick in the neck from staring up at the tricolour-lit windicator.

Autopilot. Agree absolutely that it should be No 2 if our lad is planning on singlehanding, but if not, then it comes well down the list.

Fluxgate compass - well its like a mag compass with bells and whistles - can set off course alarms, or tacking angles. Nice but far from vital.

Chartplotter in last place. Let's face it, the things are only a few years old, and generations have lived without them. It's a small window onto a chart, with a dot in the middle that shows where you are. Well you should (must?) have a proper chart anyway, and there are plenty of other ways of knowing roughly where you are on the chart without hassle, and with a little hassle of knowing almost exactly where you are.

But as in my earlier post, knowing exactly where you are hardly ever matters except at the begining and end of a passage (and maybe one or two hazard points in the middle). After all, if you're driving from London to Manchester, it doesn't matter whether you know exactly how far up the M6 you are - only that you are heading in the right direction and that Machester will eventually heave over the horizon.

You listed Navtex, and I'd agree it's worthwhile on longer passages, but I suspect TimE is going to spend his time in range of Radio 4 and Coastguard safety broadcasts for a while yet. I must say, my Navtex produces so much useless (to me) information that I don't actually look at it very often. The fact that Mizen Head light is operating at reduced power doesn't matter much if you're going from Chichester to Poole in daylight.

And wind vane steering. Yes, we'd all love that - in fact I've got the brochures - but if you leg it around your local marina, how many boats have it? One in a hundred? Fewer?

Anybody else want to join in?

 

[billmacfarlane]

Why not ? Obviously the most essential piece of kit is a magnetic compass. Couple that with a device to give you distance run and a chart of the area you're sailing in and you've got the basic, essential navigational system. You can plot where you're going , calculate your position and put it on the chart.
Considering the price of log/echo sounders as a package it would be daft not to buy one so your basic system includes an echo sounder.
Safety ? A VHF for communication , even on a trailer sailer I think is essential. It lets you listen to weather forecasts , put out distress calls and talk to the coastguard. As far as I'm concerned with that lot you've got the essential though basic navigational kit.
If you want to add on to that I'd start with a GPS set. If a budget is tight then a hand held one , that you can turn on ,if and when you need it , shouldn't break the bank. If you get a fixed set , running from the batteries so much the better.
Wind instruments ? It's important to guage how wind speeds affect your boat , but you can do that by feel and as one who sailed for 20 years without them and never really felt the need for them , I don't think they are an absolute essential , more a useful tool.
Radar ? Not for a budget concious 25 trailer-sailer owner. I can't see that it would get enough use and would the trailer-sailer have enough battery power to run it efficiently ?
Chart plotter ? Not an essential but if I bought a fixed GPS if I had the money spare I'd consider it. Reasons ? There's some useful tools in them e.g taking bearings to a fixed point that you can do instantaneously with a chart plotter. Might be useful in a lively sea where trying to do it on a chart is detrimental to your gastric juices. Not essential but could be useful.
Lastly autopilot ? Practically essential if you are sailing singlehanded but with a crew not so much so.
I enjoyed that though I'd better go as my boss is looking at me suspiciously. Have a good weekend all !

 

[david_e]

Tim,

My situation is similar to yours. My boat had the log/speed/depth/dr with it, I use the depth and speed mostly. I put a bulkhead compass in for safety reasons more than anything. This, together with charts, is enough for most of the day-sailing you are likely to do, and if the budget is tight. If you want to spend more then fine, I am not so sure about autohelm because if the boat is lively on the water then you will need to be at the helm and trimming the sails as you were with the dinghy. Having said that I don't have one so can't speak from actual experience. Again it depends on your priorities and what you want to spend your money on. One other point is that if you upgrade to a bigger boat you might not need to take this kit with you and if your boat is laden with lots of kit it might be overpriced when you come to sell it, always an issue at the cheaper end of the market.

 

[Piers]

Tim,

I suggest you talk with Dave Wellcome of Raymarine. He's an engineer supreme, knows his stuff, has been with Raymarine for years (when it was known as Raytheon) and will offer execellent advice. (He spends a lot of time with ipc in one way or another).

02392 693611 and when answered by that awful automatic machine, dial extension 1614. Tell him I suggested you called him.

Piers du Pre
MBM Cruising Club enthusiast

 

[Guest]

My opinion, for what its worth :

Essential is Safety of life, then communication, then knowing where you are.
Nice is depth, speed and wind
Luxury is Radar, Plotter, Autopilot.

Now I decided to go for :
Flares
Fire extinguishers
Compass
Proper charts
Manual gas Life-jackets NOT buoyancy aids
HH compass
Fixed and HH VHF
Echo-sounder
HH GPS and bracket / 12v lead
Speed log
Autopilot
Navtex

That's it. I look at other things - wishing that I could afford them and decided that the l;ongest trip I normally do is about 4-5 days, and mostly Solent / South Coast based ...... why spend any more ?

The other items can be built up over a period ......

Finally I would like to say that the Autopilot, actually mine is a automatic tillerpilot .... is something that I will never give up ! I normally sail with a partner, but its marvelous to enjoy boat time not worrying about the tiller etc. all the time ! I still keep the eyes open and a good watch ... but I now can enjoy a relaxing drink, I have a wandering lead allowing me to venture up the deck to attend to things with the controller in hand etc. etc.

So .............

 

[LeonF]

Charles always appreciate your learned comments. I took heed of your single handed anchoring advice some time ago and it all went smoothly. Can you add to your comments about Raytheon being not the best etc. I currently have an autohelmST4000 and St50 depth and some very old Hercules 190 which are faulty. Am planning to replace with St60 wind, speed, multi and a Silva Star GPS repeater. I would like to be able to use the auto to steer to wind or waypoint. I have a Magellan 1200XL which hasNMEA. Any suggestions would be helpful. Thanks

L.A.R.Ferguson