Thx tangent ...here I can get 1000gb 4gmobile internet for around 20 EUR per month that will be more than enough ...
I see that Asus routers are 19 v so maybe I can use STEP UP BOOST MODULE CONVERTER from 12 to 19 v 5a .?..have house battery and solar 200w
cellular typically requires a special router.
cellular uses carrier grade NAT, you typically can't get remote access directly. You have to use a different approach that uses NAT Traversal.
You also have to power the camera, they also like a nice stable power supply. Most behave best on 48V 802.3af PoE, a handful of specialty cameras are more tolerant of battery voltage.
A some form of buck-boost converter, with some solar and a deep cycle battery should be workable.
Math is required. Battery capacity in amp hours * 12v = watt hours. Add up total wattage of everything you indent to power divide by 0.8 for some inefficiency, then divide battery watt hours by this number to see how long battery will last.
you get the idea.
Presumably there are some other things that also use power on the boat...