Unless you want to look at a "ruggedized" laptop, which I wouldn't recommend as they are usually ruggedized for desert environments versus
marine, there is really not a lot of difference in picking a laptop for a boat than for a home or office ashore. Start with the basics for making a choice - Apple vs Windows vs
Linux,
price range, preferred size, etc. I'd also look for one for which you can get a 'car charger' - i.e. a 12v
charger that is not just a small
inverter. This is fairly easy if the laptop uses a usb-c port for
charging, and makes using the laptop aboard more energy efficient.
Screen brightness could be a factor if you plan to use the laptop in the
cockpit sometimes.
It is one of those cases of too many good choices, though with
current supply chain issues I'd verify whatever you choose is actually in stock before ordering.