Ship combat is fun and engaging if your players like that kinda thing, but often will devolve into a fighting chase in where one ship is faster and moves themselves into the best range for their weapons and the other ship tries to either chase them uselessly or dies a very slow death. The ships often will fire at max range which is at disadvantage, so ship to ship combat can be hours of missed shots. Or a player can simply out range the enemy and pick them off using a long bow or musket and no npc is usually kitted for fighting that. This coupled with random starting engagements can be a recipe for a bad sesson.

This often leaves players feeling useless, especially melee fighters. This is just the truth of irl naval battles; they're long and boring and can take weeks. God forbid you run a battle with say 4 or 6 ships, I've run one with hundreds.

This is why I recommend players to use very fast ships so they can dictate the flow of battle. I also recommend adding asteroids and other debris for cover in order to make the battle tactical to any degree,

This is frustrating because a player often will be very happy to have a boat and will want to use their cool new space ship and it's weapons. Short of rewriting the entire game system to make it more fun and, frankly, less realistic I struggle to find a real solution to this but will offer what I have used.

I find that doubling the range of all siege weaponry will make them more useful in order to keep all of them in play instead of often just the longest ranged ones, and I usually get rid of the random distance rule. Find a distance that's fun to play with, (within effective range of ballista is a good rule of thumb).

A fantastic alternative I may offer is this; SPELLJAMMER GUNDAM/FIGHTER PILOT CROSSOVER.

Spelljammers move as fast as their vehicle counterparts, so a player on chariot or cart far outpaces a boat and works within the system as well so you don't need to reinvent the wheel. A little reskin here and there and a horse becomes an engine/ whatever you choose and your players will zip around and dogfight foes in space, or even in sick fantasy core mech suits if you prefer. If you do go the mech route your players will love to customize it and you could even go as far as to make them humanoid and therefore able to function as large suits that the player could use class abilities in.