Why would it be naval?! Because you want it to be? -Dmitry
But of course, my friend, of course!
Still could be infantry. I was guessing naval because hilt is a known marine pattern and straight blades were popular with naval and finally because it appears to be a 'one off', something you wouldn't see in any other service at that time (army, artillery, infantry had their specific models/patterns) except private purchase. Boarders Away addressed these types and had some great ones illustrated...