Palo Alto would do what you want. PA410 or 420 would probably do for your ships. They’re not at all rated for harsh conditions, but they’re about as robust as you’ll find for basic network gear. If you get a PA for the home office as well, you can use their SDWAN for connecting everything.
For switching…how many ports do you need on each ship? I’m using Unifi industrial switches in our manufacturing plants. They stand up to the Texas summers in a highly alkaline environment. They’re only ten ports though (8 poe).