Pirates are often portrayed as wearing normal seamen clothing and using sabers, pistols, and muskets. But wouldn’t it make sense to use spears/pikes for their superior reach and light armor like the ones the Conquistadors wore to at least protect against light injuries?
There’s a weapon literally called a “boarding pike”. It was about a 6 to 8-foot polearm, often with a hook. Its purpose was what is on the label, to be used in boarding and repelling boarders. With the often damp conditions, frequent rain, and limited use of firearms, long firearms were used as a shock weapon and multiple single-shot pistols would be carried at one time.
That’s why swords are so heavily associated with pirates and naval battles in the age of sail. By the time you go to reload in close quarters combat, you’ve been stabbed twenty times (which is why some pistols even came with a mini-bayonet) After that, if the victim was still resisting (actual pitched battles between pirates and their targets were rare), then it became a hand to hand fight.
Boarding pikes, with their hooks, could be used to grab ropes, dig into the wooden rails and hulls of ships, and into people. Obviously. They’re simple easy weapons. It’s a sharp pointy stick.
As far as armor, they would be less common, in fact, we can’t recall any accounts of pirates in armor (at least among Western Hemisphere pirates) What would be the point? They’re heavy so if you fell overboard it wouldn’t help your swimming situation (a surprising number of sailors in the period couldn’t swim), most pirate attacks ended without combat (they usually went with shock and awe to make people surrender before a single shot was fired), and trying to scrabble over rails, ropes, barrels, livestock cages, and the other items found on the deck of a ship in a metal breastplate would restrict your movement.
Besides, by the time of the Golden Age of Pirates (roughly 1700 to 1730) armor had largely fallen out of use. Perhaps some seadogs, freebooters, corsairs, or others from the 15th, 16th, or even 17th Century would have had one, but even then they would have been rare.
To understand why armor and even advanced tactics were largely unnecessary for pirates, you have to understand that the big galleon vs. galleon/ship of the line fights you see in movies involving pirates were so rare, they’re actually notable moments in history.
Pirates, despite the romanticism of community and freedom, were thieves. If you’re dead, you’re not spending those coins on prostitutes and booze. Pirates preyed on merchants, not treasure galleons for the most part. Even when they did they picked off stragglers or snuck up in the night.
Merchants weren’t heavily armed and were not inclined to fight. Simply running up the flag and chasing them, maybe a deliberately missed shot or two, and they surrendered. More often than not, when a pirate ship came across a well-armed naval vessel, they tucked tail and ran. Most fights between a pirate crew and a merchant crew ended pretty quickly. Common sailors of the age weren’t exactly paid well, often disliked the captain, and had no inclination to fight.
Pirates didn’t even want to slaughter and rough up a crew. If you killed everyone, they’d be more likely to resist. Mercy was reserved for the common merchant crew (because guess who the recruiting pool was), death, and torture for the merchant captain.
2. Little, Benerson The Sea Rover’s Practice: Pirate Tactics and Techniques, 1630~1730.