The Team Red: Red Rover name had a lot of resonance. The kid's game. The idea of roving around. Rover is a euphemism for pirate. Cool.
Synonyms for rover turned up ranger and wanderer, neither of which are piratical in nature. Wanderer seems undirected. J. R. R. Tolkien has this quote "All that is gold does not glitter, not all those who wander are lost". Wanderer is sort of cool. And this quote is about a specific wanderer.
Being a fan of Lord of the Rings, the name Red Ranger crept in our heads to stay.
The dinghy could be "Scout" or "Red Scout" or similar diminutive form.
Aragorn's loaner horse in Rohan was "Hasufel". Aragorn's sword was "Anduril". Not right for the dinghy.
The guest coffee mugs could be labeled "Aragorn", "Faramir" and "Halbarad", the three rangers named directly in Lord of the Rings. Plus you've got "Arwen" and "Éowyn", the warrior queens that loved Aragorn and Faramir.
There's backstory with Aragorn's entire lineage of rangers: Aranarth, Arahael, Aranuir, Aravir, Araglas, Arahad, Aragost, Aravorn, Arassuil, Arathorn, Argonui, Arador. That's a lot of similar-sounding names; there's some prefix thing going on there that's cluttering up the name space.
We only have four coffee mugs.
This can be taken way, way too far. For example, we could use the two kingdoms (Arnor and Gondor) to name the two cabins or two heads. The Abyss, the deep bilge under the drive shaft, could be Moria, or Khazad-dûm. Let's not go quite that far with this name thing.
Plus, there's all the Lord of the Rings back story to draw on also. There's a boat named Vingilot (Wingilótë) sailed by Eärendil into the undying land of the Valinor and eventually into the heavens to become the morning star ... too much. And Tolkien's Elvish words are hard to say on the radio. Even the translation (Foam-flower) might be a bit goofy-sounding on the radio.