I've been thinking about Frog God Games' Razor Coast campaign lately, which led me to think about the boarding axe. The boarding axe was a common maritime tool used for a variety of purposes, such as fire fighting, gathering firewood, smashing through doors, walls, etc, and of course, battle.
Boarding Axe Function and Form goes into much more detail about the various designs of the axe as well as its many varied uses. It's kind of an interesting read.
Based on what I've read there, this is what I've come up with for a boarding axe for 5e.
Boarding Axe 10 gp 1d6 slashing or piercing 3 lbs Versatile (1d8), special
The boarding axe's spike may be used as a crowbar, granting advantage to Strength checks where the spike's leverage can be applied.
So what do you think? Balanced? In need of some work? Let me know.