For my own D&D 5e campaign, which is based mostly upon the high seas of various worlds, one background for a generic sailor just didn't work. On the coast, everyone sails. Because there are many different types of sailors and nautical personalities, I felt that there needed to be more variety than just one generic sailor so I created five additional nautical backgrounds to supplement the original sailor/pirate. They are the merchant sailor/smuggler, the marine, the fisherman/whaler, the jack tar, and the deep water sailor/explorer. It is my plan to release one each day of this week. This is the second one. Here is where you can find the merchant sailor/smuggler, if you missed it. I hope you enjoy the marine/artillerist.
War at sea was both your life and your bread and butter for a long while. Sailors may sail the ship, but you protect it with blood and steel. With your brothers-at-arms you learned the better points of coastal raids, boarding ships, and repelling boarders from your own. Whether you served in one of the great navies of the world, in the fleet of a merchant prince, or just as a hired thug for some petty warlord, you've learned your trade well, but it has left its marks upon you.
After choosing this background, you must work with the Dungeon Master to determine the name, type, and history of the ship you served upon, your experiences during the time of that service, and any NPC's, friends or foes of yours, that might show up in the campaign at a later date. At the start of the game, your character has very recently been discharged from service. You should also determine with the DM the reason for your dismissal.
Skill Proficiencies: Athletics plus your choice of either Perception or Intimidation
Tool Proficiencies: One type of Gaming toolset, Vehicles (water)
Equipment: A favorite short weapon (e.g. dagger, club, hook, razor, etc.), a trophy taken from a defeated foe (roll or pick something appropriate from the trinkets table on ppg 160-161 in the 5e PHB), a set of bone dice or a deck of cards, a set of common clothes, a belt pouch with 5 gp, and a large canvas bag.
Feature: Marks of Service
You have marks of service from your time as a marine. Whether it is a scar, a tattoo, a certain haircut, a style of coat you wear or just the way you stand, nearly everyone can tell that you are a former marine. Most commoners will easily yield to your polite (and even not so polite) requests. They may even buy you drinks if they know of your deeds and respect them. On the other side of that coin, you also have enemies who will look for opportunities to get back at you or kick you when you are down. Marines give respect to former members of their service, but not so far as to endanger their own mission. Former marines can always get meals and a bedroll in the common room, provided they are willing to train recruits while they stay and that their stay won't be less than 8 weeks.
Please refer to the Suggested Characteristics section of the Soldier background on pages 140 and 141 of the 5e PHB to determine your personality trait, ideal, bond, and flaw.
Variant Marine: Artillerist
You live to fire your artillery at enemy ships. You love to see the pretty colors when their sails burst into flame. You love the splintering sound of solid ammo tearing through their hull. To your friends bragging about their fights you say, "Yeah, sure. Smashing people is nice, but have you seen what I can do with this beauty here. . ." You have learned all there is to know about shipboard weapons for your setting. Whatever is appropriate to your campaign, whether it's catapults and ballista or bombasts and cannons, you know how to operate it. Once again you must work with the Dungeon Master to determine the details of your background and the types of weapons that you know.