Here's the rest of what we had originally intended to be one article (Navigation, Electronics & Communication) but, because of length, split into two (Navigation; and Electronics & Communications)
Remember that all marine electronics that transmit need to be included on your FCC license. That includes SSB, EPIRB, and RADAR.
LORAN will be of very little use to you. Past Nassau you will have to enter additional secondary factors manually. Somewhere in the southern Bahamas or Turks & Caicos it will stop working altogether.
Greatest thing since sliced bread! Don't leave home without one! I know I said early on that you could do this cruise with no electronic aids, but why would you? We paid $2800 for our Trimble and I thought it well worth it. Why would you not buy one when they now cost only a few hundred dollars?
And now another history lesson. GPS was created in the 1970s so that US nuclear missile submarines could accurately determine their positions. It seems that to shoot a missile accurately several thousand miles, one must know precisely where one is when the missile is launched. This system was never planned to be released outside the military. Then the Soviets shot down Korean Airlines flight 007 in 1983. The Reagan administration decided that had that plane had GPS it would not have strayed over Soviet airspace and so the decision was made to release the system for commercial use.
I remember reading William Buckley's "Racing Through Paradise". He had been loaned an experimental GPS receiver built by Hewlett Packard. It was as big as a microwave. Now we hold them in the palms of our hands.
The GPS system consists of a constellation of 24 (I think) satellites in low polar orbits. That means they go over the North and South Poles, sort of following the lines of longitude. They are about 200 miles up and have been launched by the space shuttle. They are not geosynchronous (like communication satellites), meaning they move relative to the earth. The other piece of the system is the receiver. To get a lat/lon fix the receiver needs to "see" three satellites simultaneously. The "fix" is actually a measure of time (and therefore distance) from the satellite to the receiver. Three satellites are needed so that receivers do not have to have super accurate (and expensive) clocks.
GPS reads out position directly in latitude and longitude. No TDs like the old LORANs. At a minimum any GPS will give your position; will allow you to enter waypoints; and will give you range, bearing, speed and crosstrack error relative to two waypoints. Fancy ones interface to other equipment and give you a graphic display of your position on an electronic chart. Interfaces allow you to display the GPS data on other devices and can even be connected to your auto pilot to steer the vessel.
Our theory was that our GPS was like an electronic sextant. We took it out, got a fix and put the GPS away. We plotted the fix on our chart just as we would do any other. We then made decisions about course to steer, etc. Our GPS was completely independent of everything else on our boat. In the event of a total electrical system failure, the GPS would have still worked. Interfacing a GPS to other devices, particularly to steering devices, scares me; too easy to become complacent and let your GPS tell your auto pilot to drive right over a reef. We have a story about this for later.
I have heard it argued that a GPS system can fail and a celestial navigation one cannot. That's a little misleading. Sure satellites could fail (there are spares up there) and sure your electronic receiver could fail (they are cheap, take a spare). But what about cloudy days or obscure horizons? Many people use electronic calculators (or computers) to do their sight reductions. Can't they fail? What about your (probably) electronic watch and the radio you use to set it?
Nope, for my money, you can't beat a GPS.
I would caution against the very cheap GPS units. When we bought ours in 1990 there was only one portable: The Trimble TransPak. As we cruised we met people with other brands of portables. Every one of them reported some type of failure. Ours worked like a gem except when Jim dropped it and then it only broke a closure on the battery compartment which was easy to replace. You have also heard about SA (selective availability) or an error the military introduces to keep the commercial units from being as accurate as the military ones. Having been a programmer for more than 25 years I certainly understand how it is possible to reduce the SA error through programming. It's my theory that the more expensive units do a better job at this than the cheaper ones. But, even the worst case error is still more accurate than you can plot on most charts.
Oh yea, charts and GPS. Your GPS is right; your chart is wrong! Few charts have been redrawn with the aid of GPS. Did you know that until the advent of GPS all charts showed Antigua a mile from where it really is? Another thing to note when using your GPS with your charts is something called "datum". The world is not a perfect sphere. Each chart is drawn using some model for its piece of the world. That model is the datum and it should appear in the legend of the chart; things like "WGS84" for World Geographic Survey 1984. You set this in your GPS. Remember that some of your charts may be based on very old surveys. Our British Admiralty chart "Haiti to Puerto Rico" had a survey date in the 1890s!
GPS has made all sorts of things possible. There is now a route from Miami to the southern Bahamas which bypasses Nassau. This is only possible with a GPS which lets you go from invisible waypoint to invisible waypoint across a shallow bank.
Be very careful about buying any list (paper or electronic) of "GPS" waypoints. Many of these are simply interpolations off existing charts. They have nothing to do with nor will they agree with your GPS. You want readings taken with a GPS at the actual location and you need the datum that unit was set to.
SAT NAV, RDF & DECCA
I guess they are still around, but the are certainly dinosaurs compared to GPS.
Nice to have but certainly not essential. "Down Time" came with an old Furuno 2400 unit and that's what we had on the trip. Newer units are a lot more compact but ours got the job done without "bells & whistles".
RADAR has three uses on a cruising boat:
1. You can see other boats and determine the possibility of a collision. This is very useful at night when crossing busy waters (like the Gulf Stream). Your eyes play tricks at night when judging distances. The RADAR is very good at this and telling you whether your target has a constant bearing (meaning you are going to collide).
2. You can watch weather systems. RADAR lets you see the varying intensity in a thunder storm and determine (like with other boats) whether or not you are on a collision path.
3. You can watch the shore. We used this for running at night along the Dominican Republic, Puerto Rico and Venezuela. In all three cases the desirable distance is 1 to 1.25 miles offshore. Very difficult to determine at night without radar.
Of course there's no fog in the Caribbean, so you don't need RADAR for that. You can also take RADAR fixes on objects just as you would visual ones, but we never found the necessity to do this.
Also remember that RADAR can only see to the horizon. Our 24 mile unit could actually see only about 18 miles. So determine where you are going to mount the antenna and don't buy a unit with more range than you can use.
Ours were electronic so I guess I'll at least mention them. We had a Signet SmartPak and a Signet wind speed/point. The SmartPak could be programmed to display a number of items simultaneously. We kept ours set to display time, speed, depth and trip log.
Don't bother except as an amusement. The Caribbean is too small to benefit from the weather faxes you can get. You can't read them accurately enough to do any good.
If you want this capability you have two choices. You can buy a standalone unit or you can get software and a device to attach your laptop to your HF radio. We had this type and I was never satisfied with the quality of the images. Now of course laptop displays are much higher resolution.
EPIRB We had one of the older type. If you want one, get the newer 406MHz variety. Never had to use ours (thank God) but we do have a story about what happens when you accidentally set one off.
Obviously all of you are computer literate or you wouldn't be reading this. Even 5 years ago computers were very common on cruising boats. Most common were laptops but we did see boats with built in desk tops.
We used ours for letter writing, inventory, games and playing with our SSB.
The letter use is obvious. We had a list of friends and family back home that wanted to keep up with our travels so we wrote form letters. As we traveled we added cruisers we met to the list. We have all these letters and will post them as part of this series at some time. Its interesting (even for us) to see how our perspectives changed as the cruise progressed.
The inventory use was invaluable. We used a simple DOS database program call Q&A. Think of all the spare parts, food items and supplies you will take. They'll be stored all over the boat in every nook and cranny. A computer is an ideal way to keep up with where they are and how many you have used. We gave each storage location a name (like behind port settee forward, or under v-berth starboard). Each record had the item, quantity, storage location and last update date. We printed the list sorted by item and by storage location. When we wanted something we found it on the list and marked off the quantity we used. Periodically we updated the database and printed a new list.
As I mentioned we had a weather fax program and a Morse code decoding program, both of which worked in conjunction with the SSB. These were more entertainment than anything else.
Computers don't like salt air. Ours failed three times due to salt corrosion. Here's what you do (assuming you are taking a notebook): Get a Tupperware-like box that the computer will fit in; get some desiccant (the type you can re-generate in the oven); keep the computer in the box with the desiccant when not in use. Do the same for your printer.
(Of course now in 2003 the main use of your computer would be for email.)
Naturally you'll have at least a VHF. You'll want it in tip top shape to get the maximum range. You might consider replacing the antenna and cable as these deteriorate over time. At least clean the antenna connections on both ends.
We found a handheld VHF very useful. Not only does it give you a backup for the big VHF, but it also allows you to communicate from dingy (or elsewhere) to the big boat.
SSB AND HAM
VHF radios are limited in range to about 35 miles. For more range you need to go to some form of HF radio. You have two choices: SSB and ham. Either has the capability to reach any spot on earth.
Here are some considerations in choosing between the two:
SSB radios are more expensive and easier to use than ham. License requirements are the same as those for your VHF - just send money. You can make commercial radio telephone calls from your SSB. It is legal to conduct commercial business on SSB. The biggest negatives for SSB are the lack of available (legal) channels for ship-to-ship chat and the fact that you cannot get a free phone patch to call home.
Ham radios are cheaper to buy and more complicated to operate than SSB. You need a license which will require you to pass a technical exam and a Morse code receiving test. You cannot make radio telephone calls and you cannot conduct commercial business. You must apply for a license (called a reciprocal license) in EVERY country you plan to visit. This is just paper work, but I understand it can be slow and bureaucratic. You CAN make free phone calls home by calling a ham in the city you want to reach and having him patch you into the telephone system.
A word about this commercial business stuff (legal on SSB, illegal on ham). Let's say you are using a ham patch to talk to a friend back home. You cannot ask him to get you such-and-such a part and send it to you. That would be defined as commercial business, at least as I understand it.
You can buy radios that are legal on both ham and SSB use, so you do not need two separate units.
Actually, a nice way to entertain yourself would be to take all the ham study materials with you and learn on the way. There are numerous opportunities to take the tests as you cruise the Caribbean. And since you are all computer literate, there are computer based study courses for both the technical and code tests.
We used our SSB several hours EVERY day. We began by tuning in the Caribbean SSB net. This is sort of like a coffee klatch for cruisers. It happens for a couple of hours each morning. It works this way. Everybody tunes to the same frequency. All calls are made and answered here then each party moves to a different channel to chat.
Each night we tuned our SSB to Herb on "Southbound II". This guy used to live in Bermuda (now Canada) and had an avocation of providing free custom weather forecasts for anybody in the world. More on Herb when we discuss sources of weather information.
Either SSB or ham should allow you to receive weather broadcasts and commercial short-wave (BBC, VOA, etc.) Why, even Rush Limbaugh broadcasts on short-wave! Of course, if all you want to do is listen, you can get a receiver for $150 that will work just fine.
As I have said, next time I would want both capabilities. Each has its strengths and weaknesses.
Oh, another thing you can do with your ham rig is send and receive data. You hook your computer to your ham set with a device similar to your home modem. You can then exchange data with other similarly equipped ham rigs. Now (2003) there are several commercial email services that use the SSB as a delivery mechanism.
This is an area that has changed drastically since our MLCS. Now you can have the appropriate cell phone and expect service (albeit a little pricey) in any of the islands and surrounding waters in the Caribbean.
CALLING HOME & VICE VERSA
Unless you are hermits with no friends and family, you'll want to call back to the US and you'll want a way to be reached in an emergency. If you take your sabbatical at the time of life we did, you'll have elderly parents and maybe generation X children. Communication with them will be important.
Of course all the places you will visit have telephone service with the US. We will discuss that in a future article.
(In editing this in June 2003 I have left the section on the AT&T High Seas service just for your entertainment.)
The only reliable commercial way to make and receive calls from your boat is with a SSB radio and the AT&T High Seas Service. You set up an account with them before you go. Call 1-800-SEA-CALL to do this. They'll need your telephone credit card number, your boat's name and radio call sign. Remember that if you cancel you home phone service while you are away you will cancel your credit card too. You can get a special AT&T credit card that is not tied to any land based number.
To make a call from your boat you tune your SSB to one of the frequencies for the shore station of your choice, probably Ft. Lauderdale. You listen for no traffic and then make your call as "WOM, WOM this is "Down Time" , WTA2000". Use your own boat name and call sign, please. The WOM operator will respond, ask your location and may ask you to switch to another frequency. When asked how you wish to pay for the call you reply "paid on board". That indicates you have an account which the operator will then check. If you have not set up an account, you can make collect calls or give your credit card number over the air for the whole world to hear. You are then connected to the High Seas operator and you place the call as you would any operator assisted call. Be brief, calls cost $5.00 per minute with a 3 minute minimum!
For someone to call you here's the procedure. They call 1-800-SEA- CALL and say they wish to call a vessel at sea. They will be asked where the vessel is. "Caribbean" is good enough. They need to know a minimum of your boat name and preferably your call sign too. They are told that you will be put on the traffic list. Several times a day WOM (and the other two shore stations) broadcast the traffic lists. You set a schedule of listening to these at least once a day. It's quite a thrill to hear your boat called along with the likes of the QEII! If you are on the traffic list you call WOM as described above. You stay on the traffic list for 3 days. If you do not respond within this time the High Seas operator calls the originating party and says they were unable to contact you. If you do hear your name on the traffic list and call back the call is charged to the person who called you. Price is still $5.00 per minute with a 3 minute minimum. You can save some money by being a little sleazy: When you hear your boat on the traffic list and call WOM they will tell you who placed the call. You simply say you'll return the call later, get in your dingy and make the call from shore. We've got some more great "sleazy boater" stories for later.
There are other marine radiotelephone services but I think AT&T's is the best.
There are also satellite systems like SatCom and Inmarsat available. However, the price is out of the range of anybody I know. I think the minimum equipment costs $ 15,000 and you need space for the satellite dish. Wait for satellite based cellular service. Now cheaper satellite phones (Iridium and Glodestar) exist, but their future is cloudy.
Enough for now.
Jim & Diane
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This page last changed on: Monday, June 02, 2003