To start, I wanted to say that this is just a few ideas that's popped into my head a few times, so I figured I'd throw it down. So, please don't expect a super ultra-polished update idea/concept. Plus it's almost midnight, so I might misspell a few things. Now, let's begin.
Muskets. I've got it on my new Discord person's little thought bubble thing (I'm not super sure about anything past Minecraft and Sea of Thieves, so bear with me), and I've been feeling this since like day 3 of knowing what Sea of Thieves even is - I hyperfocused and learned literally like 90% of what there is to know like day 1 so that took a while - and that's been like 6 1/2 years, so here it is: An Eye of Reach optimised for medium to long-range engagements. While it wouldn't have a scope (so super long range might be a little tough), it would still possess a relatively long time to bullet drop and a similar (maybe VERY slightly shorter) reload time. The bullet drop-off could be a bit shorter than the Eye of Reaches', but it is important that it is still a fair bit longer than, say, the pistol. I think this could be an interesting new weapon that I don't think would have a SUPER huge impact on the game - at least not negatively - and it is only logical that we get it at some point - pirates used muskets a LOT, sometimes even more than their swords, pistols, and knives, as they were a fair long-range option (for the time period) that didn't absolutely demolish their targets' ship and cargo. I'll probably die on this hill, though I will be honest and say I don't see too much of a reason for their to be a battle to kill me on it.
Portable Cannons! Now, this is one of my favourite concoctions! Now, for balancing, I'm not 100% sure if they should be deployable on ships, lest somebody use them as fore-guns, or aft-guns, but I DO think these make sense to have in Sea of Thieves. Maybe they aren't too common, maybe they cost a pretty penny from the Shipwright, and maybe they take a while to set up. Here's what I've got: You can purchase these artillery-level weapons from the Shipwright for 6,750 Gold each, or find them in the Storeroom of a Sea Fort, as well as in the Vault of Skeleton Forts (1-2) and Forts of Fortune (2-3). They come in two seperate pieces - the Cannon Base and Cannon Barrel. Each must be carried separately, and act like any large Treasure items - no sprinting! - and are quite heavy, causing Pirates to sink (though not super quickly) if just floating still in the Sea, and slowing their ascent to the surface. To use, place the base down in the desired location, facing whatever you'd like to shoot (so it always places facing away from the player). Now, take the Cannon Barrel and fix it to the base. I think this should be a fairly long process, so somebody can't just 'slap' a cannon down anywhere - maybe a 2-second prompt saying "place cannon barrel", followed by a second prompt reading "fasten cannon barrel", taking around ~6 seconds. This means it would be a fairly long process, but not so long as to disrupt gameplay too much. They can now be used like any regular Ship cannon, firing any ammunition, pets, and pirates alike, and being able to aim 50 degrees to each side, for a 100-degree total rangle angle. I think this would be cool for people that like to roleplay and 'take over' Skeleton Forts and Sea Forts - hey, maybe I should get that down as its own thing?? - as they could arm any islands' shores with these guns. And for further balancing, maybe you could only buy ~2 or 3 from the shipwright, and on ships the prompt to place and fasten the barrel on the base could say something like 'too unstable to fasten' or something like that...
Swivel Guns are up next! You've all (probably) seen the small swivel guns (that's their technical name, though they do say 'cannon', which is also technically not wrong as it is a powder-propelled - well, back to the idea...) on Sea Forts and on the front of aptly named cannon rowboats. I think it would be an interesting idea to make these their own thing, though, of course, with some limits for the sake of balancing. These could be bought, like the aforementioned Portable Cannons, from the Shipwright, this time for only 4,250 Gold, as they are smaller and generally more situational in use. Now, these could be used in two main ways: Arming ships and arming rowboats. On rowboats - specifically regular, non-harpoon rowboats - the Swivel Gun can be mounted on the front, making it, in essentiality, a cannon rowboat. Now, this can also be done in reverse. If you find a cannon rowboat in the wild, you could also remove the Swivel Gun and it would be a normal rowboat. The second way to use a Swivel gun is to better arm any of the three main ship types. On a Sloop, you could place the Swivel Gun on the sitting prompt in the back lower deck, by the map table, on either side. This would provide a more out-of-the-way location, while also providing slightly better protection from gun and cannon fire. On a Brigantine, I would personally recommend a slight change to the railing on the back, just so there's a relatively flat-ish spot to mount the Swivel Gun. Somewhere between the main cannons and the helm. On galleons, the best place I can think of is on one of the posts on the Poupe Deck, by the helm. This would mainly provide a more easily-accessible cannon for the helmsperson to access, rather than needing to run to the main line, as it is the only ship type with a cannon for every crew member - a personal nitpick of mine, I'll admit - and therefore make the teamwork a bit better - now the helm can do more than manage the wheel and the back sails! - for this massive ship. Now here's the balancing part. First of all, it would take a fair amount of time to Mount the Swivel Gun on the railing - maybe around 5 seconds would be fair - as well as being able to be knocked from its perch after enough close hits. I think it would be fair to say that on the 5th shot, the Swivel Gun will be knocked from its perch, and left to lie on the deck. This is because sometimes in the heat of battle, it can be difficult to get time to 'Refasten Swivel Gun' (as the prompt would say) and keep firing. Refastening the gun should only take a second or so, because consistent fire could still knock it off before you get a chance to use it, but it also wouldn't interrupt the gameplay too much. I think Swivel Guns could potentially add a new layer to gameplay, allowing a sense of unknowing of whether or not the ship you're chasing could turn about with that extra cannon, or not. Note that these WOULD carry over on Captained ships, like rowboats, are NOT recoverable from sunken players' ship (as they are too heavy and sink into the deep with the ship) and only save over if fastened to the given locations.
Lastly, a few smaller quality-of-life ideas. First is my favourite - I think charter ships should spawn with a non-cannon, regular 'Lantern' rowboat attached to the back - no specific liveries, just something to make it feel like you're getting the 'complete package'.
I also think rowboats could be sold by the Shipwright, spawning next to the dock, but not right next to the ship. To make sure one can't simply buy their way into commendations, I think it would be wise to make only the default, plain rowboat available at the start, with other liveries (hopefully including a Midnight Prowler livery - I NEED a black-painted rowboat!!) being unlocked as the Rowboat Revelry Commendations are completed. Maybe there could be a Legendary livery unlocked by being Pirate Legend, and a Soulflame Rowboat (minus the Keg) unlocked by getting Reputation 100 in Reaper's Bones! I think 7,500 Gold would be a fair price for these little boats, and maybe only 5,000 for the unremarkable Sailor-liveried ones.
Another smaller idea for ya'. Freshwater barrels on ships! Not everybody wants to drink grog ALL the time (Lord Flameheart, what pirate have I become?!), but most importantly, I would LOVE to fake drink with another crew so I can betray them while they're blood drunk while completely sober! I think it would be fair to put the Freshwater keg in the keg-holder under the Grog keg, just because I do think it's less likely for pirates to want quick access to water.
I also want to put forward the idea of a Better Sitting Around update, which would ideally allow a pirate to pull out food, instruments, and any other inventory items APART FROM WEAPONS. This is mostly because on Xbox, Y is the weapon button AND the third-person button, but still... I don't think it's a super great idea. Part of this idea is also the ability to roll up the map on the Map Table of a given ship, as well as then pull out benches (like the ones found in the taverns) from underneath it. On larger ships, there should also be a smaller wooden seat on each head of the table, to accomodate a couple extra folks.
Lastly, a more risky idea on the side of controversy, I think there should be a non-ghostly Wraith cannonball, called a Powdershot, or, the name I greatly prefer, a Kegshot. They would drop from Skeleton Fleet boss ships, with the trade-off being that the boss could also fire these roughly every 1/25 cannonballs, just so it won't spam 'em, and you'd get maybe 1 or 2, MAYBE 3, but I think lower numbers would be better because Skeleton Fleets are pretty easy to complete these days. They would literally be red/orange cursed cannonballs that are KEGS for your CANNONS! Fire included, by the way, hence their lesser spawning, though only a small amount. They would keep the lesser player damage of the Wraith Cannonball, though, because Keg-level damage in a cannonball like that is a bit much, even for me! I think it would also be cool to get one per barrel on the Burning Blade, which could also fire them when crewed by Skeletons of the Flame, but not by the Skeletons during the player-controlled phase of the world event.