Storage, meaning the size of the computer's hard drive(s), is less important than it once was, because external drives are now large and affordable. However, externals may be slower than the machine's native drives, and so you want as much storage as you can afford built into the machine. A laptop with 80 gigabytes is sufficient, and 100 gigs or more is preferable. Another factor is the speed of the drive(s), which is measured in revolutions per minute. Drives of 4,500 RPM are acceptable, but 7,200 RPM is better.
Additional drives, such as a CD or DVD drive, are often debated by users on land because they add weight to a machine. For an onboard computer, however, a DVD drive is worth the weight. You will want a DVD drive because many navigation programs and charts load from DVDs. Again, you could add an external drive later, but it's better to get it built in, if you can.
One thing that is easy to forget is the number and type of ports. Virtually all machines come with several USB ports; an Ethernet port for high-speed Internet access; and connections for an external monitor and mouse. But if you require more ports, or something special, make sure it is included on your machine. For example, you might want a Flash card reader or you may have an Internet air card in the older PCMCIA Card format. If you want to make use of these devices, make sure that your machine has the ports built in.
A USB air card provides easy Internet Access.BATTERIES AND PERIPHERALS
Battery life is another parameter that deserves your attention. This is one area in which reviews can be helpful, especially those that actually test the machines. Pay attention to reviews that track real performance, not just the manufacturer's claims.
If battery life is important to you, meaning you plan to use the computer for long amounts of time without AC power, then consider buying a larger battery and using the stock battery that came with the machine as a spare.
There are also some peripherals that are best bought separately, because they will be cheaper.
Be sure you buy security software, such as Norton or McAfee, as soon as you start using your machine, to protect against viruses. You can also run programs like Ad-Aware and Spybot, which protect your computer in different ways. Both have free versions, as well as more full-featured applications that require payment (see links).
In order to take advantage of most navigation software, you will want an external mouse with a scrolling wheel, which you can buy in a wired or wireless configuration. If you plan to use your computer for real-time navigation aboard your boat, you will need a GPS that plugs into a USB port. Two reliable units are the GlobalSat BU-353 or the Garmin GPS 18.
You may also want an air card, which you can get through mobile providers such as Cingular or Verizon. These devices plug into a USB port and function like a cell phone to provide high-speed Internet access. Finally, be sure to buy a padded case for your machine – it's worth the money.
Glen Justice is the Editor of Mad Mariner.
I have used my IBM Thinkpad R40 on board but find that the screen is unreadable in most sunlight situations. I see that some of the marine computers offer day light readable screens. Do any of the mainstream manufacturers (non-marine) offer daylight readable screens? What spec determines this? In other words, how can I tell if a screen will be readable from the specs?
Thanks very much. Interesting series.Â
Ed Waterman
Hi Glen,
Good story - focus is on the right things.
Let me add a couple words about the Mac: I currently use a new Mac Book on the boat and run Nobeltec VNS. As you know, the new Macs are  dual-boot machines - they can use both OS X and Windows. I prefer to boot the machine in one or the other, not the both-at-once option. It works great using XP Pro and all the interfaces work, including a SeaCom 4 to 1 serial to USB adapter box. I can also send routes to the Raymarine E chart plotter. As per your recommendation above, I only use the nav application on the Windows side - no email, no Word, etc. As the Mac is superior for those functions, I do all that on the OS X side (and am better protected for internet use).
The software reviews are very useful - especially your focus on the charts. Keep up the good work. HNickÂ
I do own and use on board of  my BI-40  Macbooc Pro Dual Core, 2.33MGHz. Using Boot Camp I have a choice to use OSX Leopard or Windows XP.
My navigation software NavSim SailCruiser (www.navsim.com) works flawlesly in WindowsXP.
Having new Mac I have it all and I am not limited just to Windows....Â
The single biggest issue with choosing a computer aboard a boat is a sunlight readable screen. There is a brightness measurement called "nits" which is supposed to be a measure of one screens measure of brightness to another. However, this indicator is often not published for many laptops. The ruggedized laptops like Panasonic Toughbooks (there are others), are made for outside field use and would be better suited to boating. Dell has a new PC that is supposedly sunlight readable and may publish the nits value. I have an HP Pavillion laptop which is unreadable in any sun. In my opinion, most PC's today have far more capability that anyone would need for normal boat use assuming it has a few usb ports for peripherals. To me, it is the screen readability that is the biggest concern. If you decide to use it as your only electronics unit (in addition to paper chart backup, always) make sure it is secured in place or it will "hit the deck" at the worst time!