Computers at sea are of course not just for electronic chart navigation. Among their handiest uses is communication by e-mail and fax. When beyond cellular range, specialized providers offer e-mail connections via marine SSB, HAM radio or limited, data-only satellites.
Once you head offshore or to areas where cellular service is unavailable, incompatible or too expensive, satellite telephone is the simplest and most convenient e-mail connection. A satellite telephone set-up is just like a modem and no additional hardware is needed. You can usually use the same on-land e-mail ISP for at sea with the convenience of being able to access your messages anywhere anytime. Even when you return home, your e-mail access follows, so mail forwarding is unnecessary.
Many sailors think that using a satellite phone is the most expensive way to communicate but surprisingly, it can be the least expensive. Since satellite telephone charges accrue by time, the longer the e-mail, the more "postage" is required. However, at satellite data-transfer speeds, lots of information can be sent in one minute. Voice time, billed at the same rate, is actually less expensive than phone calls made through the SSB high-seas operator (approximately $5 per minute with a three-minute minimum.) Yes, satellite communication equipment is costly, but it doesn't require any additional modem hardware and most sailors on long cruises find a fairly fast payback of the cost of equipment through the rate savings.
You can also use SSB for e-mail, but you need a radio that is compatible with a special radio e-mail modem. Radio e-mail requires some set-up and, unlike satellites, is subject to atmospheric conditions. SSB e-mail is not legally accessible on land, so a forwarding arrangement to a second shore ISP is necessary when accessing away from your boat. If you already own a compatible radio, SSB e-mail can be relatively inexpensive. If it's not compatible, you'll probably need to add $2,000 to the cost of SSB e-mail equipment, plus the time to install and learn how to use it. The rates for SSB e-mail transfer are billed on the basis of message size, bits or characters, rather that connect time. Typically, SSB rates are between 20 and 100 times that of satellite.
A word about the much talked about Iridium system. Motorola's Iridium is less expensive than other equipment and the rates will be equal to satellite telephone. Despite its on-going financial concerns, Iridium continues to aggressively market, recently announcing airtime rate reductions and lower-priced equipment. (Rates of $1.59 to $3.99 were quoted by the company in its July 1 release.)
For more information on communication at sea via SSB and satellite, check Complete Cruising Solutions via www.waypoints.com or call them at (800) 584-4114. They are among the recognized experts.
|Bit: (BInary digiT) A single digit in a binary number (0 or 1). Within the computer, a bit is physically a transistor or capacitor in a memory cell, a magnetic spot on disk or tape, or a high or low voltage pulsing through a circuit. A bit is like a light bulb: on or off. Groups of bits make up storage units in the computer, called characters, bytes or words that are manipulated as a group. The most common is the byte, made up of eight bits and equivalent to one alphanumeric character.|
BPS: (Bits Per Second, or bit rate) Speed at which bits are transmitted.
Byte: The common unit of computer storage, made up of eight binary digits (bits). A byte holds the equivalent of a single character. For numbers, a byte can hold a single decimal digit (0 to 9), two numeric digits (packed decimal) or a number from 0 to 255 (binary numbers).
Baud: The signaling rate of a line, which is the number of transitions (voltage or frequency changes) that are made per second. The term has often been erroneously used to specify bits per second. Baud is equal to bps only at very low speeds.
Modem: (MOdulator-DEModulator) A device that adapts a terminal or computer to a telephone line. It converts the computer's digital pulses into audio frequencies (analog) for the telephone system and converts the frequencies back into pulses at the receiving side. The modem also dials the line, answers the call and controls transmission speed, which ranges up to 56,000 bps and higher.
URL: (Uniform Resource Locator) The address that defines the route to a file on the Web or any other Internet facility. The URL contains the protocol prefix, port address, domain name, subdirectory names and file name.
|Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)|