in the Marine Environment
One of the most often asked questions is whether ordinary computer gear can survive in a normal marine environment. Here then is a story about four different PC compatible computers which have been to sea on a small boat - one for over 8 years!
Our boat is a 40 foot monohull, aft cockpit sloop. It is arranged in a conventional manner with the chart table just forward of the companionway hatch on the starboard side. While it's the ideal place to operate the computer(s), it by no means is the driest spot. But, all of the other possible locations were too near hatches where seawater might leak or splash onto the machine.
There are (or 'were' as I shall explain) four different machines on board our boat. The original computer was a laptop purchased in the mid 1980's. An ancient 8088 beast that still works well for the occasional weather fax or game of 'Tetris'. Next came a 80286 laptop, then the 486DX33 notebook and finally a full sized 486DX66 desktop with a 14 inch color monitor!
These computers were NOT 'marinized' or otherwise sealed from the environment. That would have been nice. Each of these machines was a 'straight out of the box', consumer grade PC compatible. (Not long ago, we met a boat with a Mac onboard and compared notes - their results were similar to ours).
The computers are used for a variety of tasks ranging from weather FAX reception, ham radio, packet communications, automatic reception of CW weather bulletins, cyclone tracking, internet email (via cellular telephone), word processing, software development, an occasional celestial site reduction, GPS waypoint downloading, and one or two other things. This, of course, doesn't take four PC's, but as technology progresses, so do the number of 'formerly powerful' computers.
Of all the applications, weather forecasting has to be the most important. Our sailing plans develop around the latest weather FAX, and upon our ability to look back at weather charts over several weeks to determine various weather patterns.
There is at least one computer in operation virtually 24 hours a day, at anchor, or on a passage, to collect weather charts and forecasts. It's been that way since 1988.
With four computers, the total exposure time to the marine environment exceeds 15 years! Here's what we found:
- POWER SUPPLY: The most vulnerable part of the computer. Batteries in the laptops and notebook (even if powered by an external source) need replacement every once in a while. Carry an extra set with you since they can be hard to find in remote areas of the world. If you are connecting the computer to the boats' 12 volt (or 24 volt) power then you must use some sort of DC Power Fault Protection like a STO.P. We learned this the hard way and destroyed our 486 notebook in the process! (See 'Disaster Strikes' below)
- DISK DRIVES: No problems have been experienced with either the 3.5 inch floppy drives or the hard disk drives in any of the computers. We have not even cleaned the floppy heads on any of these machines in the last six years!
- KEYBOARD: During the very wet New Zealand winter of '95 (June to August), we started to experience some 'sticky' keys on the full sized desktop keyboard. The keys operated normally after a few moments of use. With the onset of drier weather the problems disappeared.
- EXTERNAL CONNECTIONS: For the most part the connections to the printer and to the serial ports of the various machines have been troublefree. But, I'd suggest using connectors that have gold-plated contacts for maximum reliability. Power connectors are the least reliable and have caused some minor problems over the years. We solved most of the problems (associated with corrosion and high contact resistance) by cleaning them and applying a small amount of silicone grease to the contacts. In one case, we bypassed the standard 'coaxial' power plug and direct wired our power leads to the computers circuit board.
- CIRCUIT BOARD CORROSION: At one time or another, I've been inside of each and every one of these machines and can happily report that there is absolutely no evidence of corrosion on any of the circuit boards or chips.
- DISKETTES: Definitely a problem area. We left some of our diskettes exposed to the warm tropical marine air in standard 'floppy boxes'. After a year or so of this, we started to get read/write errors. Some disks were totally useless. Investigation revealed that the surface of the disk media had become a 'garden' of mould or fungi. We were not sure which it was but the result was the same. Large amounts of data had been lost.
On a boat in the middle of the ocean or in some remote anchorage, you can't just go down to the store for a new box of diskettes. And there are no 'data recovery' services available. So you use what you have and experiment. So with a cotton swab and some isopropyl alcohol, we scrubbed the media surface until the growth was visibly removed. We let the diskettes dry for a few minutes and then to our surprise, over 90 percent of them worked normally!
- VENTILATION: All of the portable computers are operated on top of a table-like' surface, i.e., a chart table, or nav station. Temperatures ranged up to 100 degrees F with 100 percent relative humidity. No problems have been experienced. The Desktop, was built into the nav station. Ventilation is somewhat restricted, but in two years of operation there have not been any failures.
DISASTER STRIKES (The First Time)
When you live on a boat, you figure that someday your precious computer is going to get wet. Well, our particular disaster came about as I was writing an article on the 486 Notebook. My partner came in to show me something and accidently knocked a full glass of water straight into the keyboard. Eight ounces of water instantly disappeared inside the computer and the screen went blank. @^*%!!! Panic.
We grabbed a screwdriver, quickly disassembled the case, shook out the water and sponged the circuit board. The keyboard was removed and left in the sun to dry. Connectors were unplugged and dried. We used a little WD-40 in each connector hoping that it would displace the remaining water. Finally the entire computer (all disassembled) was put into the hot tropical sun to dry out.
The moment of truth came a day later when we reassembled the unit and it worked!
DISASTER STRIKES (The Last Time)
One of the nice features of that little 486 Notebook was that it would operate from a 12 Volt power source on the boat. Unfortunately, one day while charging the batteries, I reached for the main battery switch and instead of switching batteries, I accidently turned the switch to 'OFF'. As you probably know alternators don't like to operate without a load; the resulting high voltage transient blew virtually every silicon chip in the computer! In a brief instant, my mistake turned a $4,000 notebook into a 'boat anchor' - a total write-off. The only thing that survived was the keyboard!
The obvious choices on a boat are Inkjets and Dot matrix printers. Lasers consume lots of power and unless you operate your computer from an AC generator, they are not too practical at this stage of their development. Perhaps someday.
We have used three printers on our boat, an Epson dot matrix unit powered from a 115 VAC inverter, a Diconix 150 powered by 12 Volts, and an HP Deskjet powered by a 240 VAC inverter. For professional results, the HP has been an excellent choice. The Diconix is great for weather fax charts. In either case, we reload ink cartridges ourselves to bring costs down. None of these printers has failed!