a notebook is for writing. why would he have a computer with him and not a phone... ya know something that require power and charging every few hours. would have been useless to him. he carries notebooks around when hiking to draw in... also as I said earlier in the US, and being from that part of Florida, notebook does not mean computer
and also mentioned this but will again... unless he used a marker, or a marker pen ink is not soluble in water. some is, but I'm assuming it is very unlikely. its soluble in most solvents like alcohol and acetone. go try it at home try out a bunch of pens and pencils... stick them in water after they dry and watch what happens
A notebook can also be a computer. They are smaller, and lighter, therefore would be a good thing to bring along if you were out on the run. You can also facetime, or many other ways, live with someone. I don't do it so apologize for not knowing more on the topic other than it is possible to talk to people over your computer so he wouldn't need a phone. Although... then there's the problem of charging the battery out in the wilderness like he appears to have been.
A notebook computer is a battery- or AC-powered personal computer generally smaller than a briefcase that can easily be transported and conveniently used in temporary spaces such as on airplanes, in libraries, temporary offices, and at meetings. A notebook computer, sometimes called a
laptop computer, typically weighs less than 5 pounds and is 3 inches or less in thickness. Among the best-known makers of notebook and laptop computers are IBM, Apple, Compaq, Dell, Toshiba, and Hewlett-Packard.