Let's talk about defining what you need in a computer, rather than just offering you a fixed configurations. Yes, we have researched certain configurations that we recommend, and can supply, for vessels in various fisheries. Among your most basic questions will be: what has to connect to the computer? Do I have more than one computer that has to be interconnected with another, even if some of those computers are built in to cases bearing a marine electronic vendor's logo?.
We will start from the outside in, then from the critical inside pieces. Start with how you interact with the computer: a keyboard (or perhaps a simpler keypad), a mouse or other pointing device, and perhaps a printer, as well as one or more video screens. The keyboard, pointing device, and printer are most likely to connect through the Universal Serial Bus (USB), although the keyboard and mouse might have an option for an older interface, PS/2, which can convert to USB with a simple adapter.The video screen uses a video connector, which, without special hardware, can run a cable up to 100 feet long, which should be adequate for all but the largest fishing vessels.
We will certainly support laptops, but we'd like you to think carefully about the reliability and maintainability of a laptop rather than a different form of packaging. Unless you opt for a ruggedized military style laptop, and are prepared to pay several thousand dollars, laptops are fairly fragile. We've seen many that aren't fastened, even with Velcro, to the dashboard, so if a wave tosses the boat, and the laptop, the next thing you may hear is a *crash*, followed, more frighteningly, with a tinkle tinkle tinkle of little parts falling off. Typical laptops are meant for office and home. You'll see them used on construction job sites and by the military, but those tend to be ruggedized.
There are plastic covers that can help protect the keyboard and display from dripping water or spray, but they aren't as reliable as the covers for full-size equipment. There is a term for a laptop that gets water into it while it's powered up: dead.
Computer manufacturers have to make lots of choices in manufacturing a laptop. Several of those choices involve how connectors open to the outside, and are fastened to the electronics inside. We've had several otherwise good laptops that had the USB or power connector break loose from the main printed circuit board. Sometimes, a really good repair technician can solder them back, if the only thing that's broken is the solder seal. It's often more than that, such as a crack in the circuit board from pulling too hard on the connector.
Laptop cases are very tightly packed with electronics, and opening them, and getting at the pieces inside, sometimes feels like removing your own appendix. Again, a highly skilled repair technician, who has the repair manuals or has been taught by an expert, can open a particular laptop case with only two hands. Some Beachwerkers thought it wouldn't be hard, and tried it...and heard that tinkle tinkle tinkle as pieces fell into the innards. We have a couple of older laptops that work fine, other than a broken connector, and we keep them around in the event we find a repair technician that owes us a favor. Sadly, if that laptop is more than 18-24 months old, it's rather likely to be obsolete and not upgradable.
Modular computers, as "towers", "desktops", or "pizza boxes" aren't as tight on space, so it's much easier to reach inside to fix or upgrade parts. There are more options with such a case than with a laptop. We certainly agree that it won't fit onto the dashboard, but we don't suggest you put it there. Rather, we suggest you put the computer case in the cabin or in a protected area behind the dashboard, and run cables to the devices that you actually need: keyboard or smaller keypad, mouse or trackball, video display, and speakers if you use them.As far as interconnecting marine electronics, like GPS, radars, radios, etc., to each other or to a computer, the best approach tends to be different for every boat. Sometimes, we find that a wiring panel, often with a plastic cover, can fit neatly under the dash. In other cases, it's better to make the interconnections in the cabin.