@captain-awol522
Skeletons are a bit more complex than you seem to think. Here's a bit of a guide, as the PvE in this game is a real menace if you don't know how to deal with it, and the skeletons very much fall into that category.
Skeletons have four different types, these are gold, shadow, plant and bone. Of these types, there are a few places you can find them. What are known as 'ambient skeletons', which you have no doubt encountered, are found here and there on islands, or manning the cannons of active strongholds. They can have any weapon save for an eye of reach (skeleton ships have snipers in their crow's nest, however EoR skeletons do not spawn anywhere else), and can also have a gunpowder keg or no weapon at all. Their spawn rates, health, and weapons vary depending on your quest, with higher level quests spawning more difficult ones, ranging from ones with 50 health (taking a mere 3 cutlass swipes, and falling to one flintlock, eye of reach, or blunderbuss shot) at lower levels (as compared to the 100 a player has), to ones with 175 health (taking 8 cutlass swipes, or 4 dashes) on the highest level voyages. If no voyage is active, or a tall tale or mercenary voyage is (not including message-in-a-bottle voyages), the ambient skeletons will be at 50 health. Skeletons do not overheal.
On bounty quests for the Order of Souls, on board skeleton ships, and on active strongholds, you can find four types of skeletons:
Bone skeletons, the most common type, are the normal ones, the most common of them all. They have no particular weakness, and no particular strength. All ambient skeletons are bone skeletons, excluding the occasional ambient skeleton captain you will find.
Plant skeletons, identifiable by the extensive plant growth on them, are weak to the cutlass. They take slightly more damage from it, while taking less damage from guns. They have the ability to passively regenerate heath after contact with water, so avoiding the shores is a good idea. Rain will also affect them similarly, activating their regeneration regardless of their location, provided they are not underground.
Shadow skeletons, identifiable by their black coloring or mist-like appearance and purple eyes, have strength in darkness. They will turn incorporeal in the night, regardless of their surroundings, unless a lantern is shined on them. Lanterns, torches and fires on and around islands do not activate their weakness, however sunlight does. They will remain corporeal in darkness for a short duration after being lit up, meaning even a lone pirate can combat them in the night. They have no particular weaknesses or strengths to or against any certain weapons. On the Fort of the Damned, a type of skeleton known as a Shadow of Fate can be found. These shadow skeletons can only be weakened by a Flame of Fate from the Well of Fates, on board the Ferry of the Damned. They are not encountered on other islands unless a ritual skull is dug up from the map dropped by an ambient skeleton captain.
Gold skeletons are perhaps the hardest skeletons to defeat. They are slower than any other type of skeleton, however they are armored with treasure. They have a very strong resistance to cutlass strikes, though stun-locking one with repeated strikes is possible, it is difficult and time-consuming. They are somewhat less resistant to guns, taking moderate to severe damage depending on the gun (flintlocks do little per shot, while a blunderbuss can one-shot some). Gunpowder barrels and cannons are incredibly effective against them, shattering any in range of the explosion, even if a non-gold skeleton would've survived at the same range. Water slows and weakens gold skeletons, shown by the rust and sparks they begun to emit when in contact with any kind of water. Leading them to the ocean or a pond is best, as the constant contact with water will keep them weakened and slowed, but do not think they are incapable of escaping should you run off inland. A bucket can also be used to throw water onto a gold skeleton, achieving the same effect, albeit temporarily.
Notably, some chapters of the Shores of Gold tall tale (particularly the 'Shroudbreaker' chapter) will have you come up against a skeleton type known as coral skeletons. They act and react identically to bone skeletons, having no weaknesses or strengths, other than overwhelming numbers.
These described above are normal skeletons, which are often encountered near or around a skeleton captain. Skeleton captains have 4 times the health of a normal skeleton, meaning that on average skeletons (sitting at 100 health), they will have 400 health. This appears to scale accordingly with other health levels. On Order of Souls bounty voyages, skeleton captains will drop skulls which can be sold to OoS representatives. On some tall tale chapters, they will drop other mission-specific items. Ambient skeleton captains, mentioned above, can be found, and will on occasion drop maps alongside their skulls, which lead to a ritual skull used to activate the Fort of the Damned. On strongholds, they will drop stronghold keys, which can be used to unlock the vault beneath the main fortress. Captains on skeleton ships do not drop anything, and do respawn. The death of a skeleton ship's captain does not stop the ship from maneuvering.
A type of skeleton known as a Skeleton Lord is also present within the Sea of Thieves. They are rare, and extremely powerful. 3 can be encountered throughout the Shores of Gold tall tale, and one, Greymarrow, can also be fought in a ghostly form as the stronghold captain on the Fort of the Damned. Skeleton Lords have absurd amounts of health, and three main moves: a teleport, which will temporarily despawn them until they reappear elsewhere (their health remains the same); a summoning move, which spawns several skeletons around them; a 'slam' attack, which causes a massive shockwave dealing heavy damage and knockback to all in range. Alongside this, Skeleton Lords will typically carry two weapons of various types, and can heal with bananas at low health. They are affected by cursed cannonballs, which is the only way to interrupt their attacks.
Skeletons range in health as well. For reference, players have 100 health. The flintlock does 50 damage per shot, the eye of reach 75, the blunderbuss 10 per pellet (with 10 pellets), and the cutlass 20 on a swipe (60 if all three in a combo are performed) and 50 on a dash.
Low-level skeletons will spawn with 50 health, making them easy prey for any weapon. Their health can alter depending on the type of skeleton they are, such as gold and plant skeletons with their resistances and weaknesses. The skeletons at the highest levels, being either level 50 OoS voyages or a voyage for Athena's Fortune, will have 150 health as ambient ones (8 cutlass swipes to kill), and 175 health as voyage-specific ones. The abundance of ambient and voyage-specific gunpowder skeletons, as well as any collected from the islands the skeletons are on, will be of great help against these.
On strongholds and skeleton ships, skeletons always have 100 health. Skeleton ships captains have 400 health, I am currently unsure as to stronghold captains' health.
I hope this helps at least explain some of the reasons for what you've been having to deal with, and possibly helps you improve at fighting skeletons overall as well.
