Here's some stuff for you that I wrote awhile ago, extrapolated from some 3E stuff as well as WoTC's take on shipboard actions from The Plane Above. Hope this helps.
Ship design guide
Adventures on the Astral Sea
The eerie tranquility of astral travel is often shattered by eruptions of sudden danger. Characters aboard skiffs or other conveyances could face magical storms, arcane anomalies, hostile ships, or hungry free-flying creatures, such as astral dreadnoughts. Depending on the game’s pace, such a moment of navigational menace can be resolved with a single skill check, as a skill challenge, or as an extended combat or action set piece.
General Shipboard Actions
The following skills can be applied to nearly any shipboard emergency.
•Acrobatics: Perform stunts requiring precarious climbing up, down, or through the ship’s masts and rigging. Tumble through falling obstacles to secure a critical piece of equipment knocked loose in the struggle.
•Athletics: Momentarily hold stressed or breaking ship pieces in place. Man the ship’s helm, executing audacious maneuvers or steering the vessel in the face of great resistance.
•Arcana: Pour additional magical fuel into the engines, momentarily (and dangerously) increasing the vessel’s speed or maneuverability (to compensate for missing crew members, for instance).
•Endurance: Perform tasks while battered and nearly destroyed; survive with minimal food and water after supplies are lost or stolen.
•History: Identify oncoming vessels by size and configuration, naming the origin and likely intentions of their crews.
•Perception: Spot trouble before it starts, determine the weak point in an enemy’s hull, or see a creature’s vulnerability.
When the crew of one vessel tries to engage and the other tries to escape, a chase ensues. If you know that a fight will ensue when one vessel catches up to the other, resolve the chase as a single Athletics check by the character at the helm. In instances when the conclusion of the chase won’t necessarily lead to ship combat, run the chase sequence as a skill challenge of its own.
•Arcana: Spot astral eddies to gain increased speed; locate nebulae or other astral bodies to hide behind; find portals allowing magical teleport to another sector of the sea.
•Nature: Spot or avoid schools of astral creatures that impede navigation.
•Stealth: Plot a confusing course while fleeing; identify a confusing course laid in by a fleeing vessel.
Conquering Enemy Vessels
In a skill challenge to board and overrun an enemy vessel, the characters contend for the opportunity to stage a fight on the enemy crew’s deck. If they lose, the targets successfully disengage before a fight can occur. Alternatively, a lost challenge could result in the fight occurring on the characters’ ship. Victorious invaders not only defeat their opponents, but can then seize control of the vessel.
•Acrobatics: Use a piece of loose rigging to swing onto the target deck.
•Intimidate: Frighten crew members into backing away or otherwise ceding ground.
•Stealth: Sneak aboard from a different direction to achieve surprise.
Allow movement attacks and racial powers to substitute for skills as the logic of the scene permits. For movement powers such as fey step, where no skill modifier pertains, ask for an Arcana check to determine if the character’s "aim" is correct, or treat the use of the power as an automatic success.
Interactions With Rival Crews
•Bluff: Fool targets into thinking you're an ally, letting you act unexpectedly and achieve surprise.
•Diplomacy: Pursuade adversaries to not attack you; determine how much to bribe to secure your freedom should things go sour.
•Intimidate: Persuade potential adversaries that it'll hurt them more than it'll hurt you.
•Insight: Identify crews intending to attack you when they're appearing friendly; make an important mental connection about a ship and its tactics.
Disable or Destroy Enemy Vessels
•Arcana: Use onboard magical weaponry (if available) to modify arcane ranged and area attacks to damage ships from a distance. This check allows subsequent uses of the attack powers themselves. Expending a daily arcane power grants a +5 bonus to the attack roll.
•Religion: Same as above, but for divine powers.
•Weapon Attack: Damage ships using onboard siege engines.
Repulse Boarding Attempts
Ways to avoid a fight on your own ship:
•Bluff: Lure an invader into making a false step or into a trap.
•Intimidate: Scare off the invaders.
•Stealth: Surprise an invader trying to move between vessels, shoving the target overboard.
Avoiding Navigational Hazards
Permanent navigational hazards are known as anomolies. Avoiding hazards may require skill challenges that use:
•Arcana: Operate the ship's instruments to detect the hazards.
•Endurance: Physically shielding an ally from the effects of the hazard and bearing the brunt of the effects yourself.
•History: Reveal the locations of the hazards to avoid.
•Nature: Predict oncoming weather conditions by observing changes in the astral eddies, wind and wildlife.
•Religion: Sensing divine energy indicating past or present activities of deities and thei agents; identify mystic runes left over from the Dawn War.
I'm also adding:
•Insight: Determine the intentions of the enemy ship.
•Intimidate: Maneuver the ship aggressively, making the other guy flinch, granting combat advantage (save ends)
•Arcana: Identify performance capabilities of the enemy ship, operate the aether drive, repair the ship, study the universe and how it relates to planar alignment and the effects of the universe on magic.
•Nature: Investigate celestial bodies like planets, asteroids, and comets, predict the orbits of celestial bodies (basically, what we call Astronomy in the real world).
•Athletics: When piloting a ship or flying mount, perform stunts like Sideslip, Avoid Hazard, Bootleg Turn, Dash, Feint (requires Bluff check), Grapple, Hard Brake, Hard Turn, Jump to Spelljamming Speed, and Withdraw if you successfully meet or beat the DC and you meet the prerequisites for the stunt.
A Matter of Scale
As noted in the Ship Design Guide, airships and spelljammers operate on a larger scale than characters do. In the Ship Scale, one square equals 100 feet or 20 character squares. For sake of convenience, don't convert a ship's Speed rating between scales; just assume that on the Ship Scale, vehicles can move faster with more open space.
Piloting a Ship
There are two different types of maneuvers possible when operating a vehicle: Simple Maneuvers, and Stunts.
Drive ♦ At-Will (Move)
Vehicles are designed to move in one direction only. You direct the vehicle forward, but turning the vehicle can be slow and difficult.
Movement: Move the vehicle a number of squares up to its Speed.
Direction: The vehicle must move directly forward along its heading.
Opportunity Attacks: The vehicle's movement does not provoke opportunity attacks against the vehicle or the creatures inhabiting it.
Terrain: Terrain affects vehicles in the way it affects creatures. flying vehicles can encounter debris fields, astral eddys, turbulence, and other aerial/astral phenomenon that counts as difficult terrain and cost an extra square of movement. If the difficult terrain requires a skill check, then the pilot makes the check.
Special: You may shift the ship one square along a forward diagonal without turning.
Stop ♦ At-Will (Move)
When a vehicle is moving, it takes effort to stop it.
Movement: The vehicle moves forward along its heading a number of squares equal to the distance it moved in the previous round. At the end of the move, the vehicle is motionless. The vehicle will not go out of control if it is stopped. The vehicle begins moving agan when the pilot uses the drive action.
Special: In Wildspace and the Astral Sea, motionless is a relative term. When orbiting a celestial body, motionless referrs to the speed an object needs in order to remain in orbit.
Turn ♦ At-Will (Move)
You turn the ship to change its heading. Heavier and/or fast ships are harder to turn.
Movement: The ship requires one or more drive actions based on its weight.
Tonnage Required Drive Actions
< 250 0
> 2,500 4
If a ship is traveling at more than half its speed, then use the next heaviest weight category to determine how many drive actions the ship uses. If a ship or vehicle is less than 250 tons, then it requires no drive actions before it may make a turn.
Direction: After completing the required move actions, change the ship's heading by 45 degrees.
Ram ♦ At-Will (Move)
You attempt to collide with another object and damage it.
Movement: The ship travels a number of squares up to its Speed. Additionally, it may shift up to one square along its forward diagonal.
Direction: The ship continues traveling forward.
Check: The pilot makes an Athletics check versus the target's Fortitude.
Success: The target ship takes 1d10 damage per square traveled before colliding with the target, multiplied by 5 + the attacking ship's weight multiplier found in the table below. The attacking ship takes half-damage, or one-quarter damage if equipped with ram. Anyone standing on either ship must make an Easy Athletics check to avoid being knocked prone.
Fail: The ship misses the target and travels forward until it uses up its movement points.
Tonnage Weight Multiplier
< 250 1
> 2,500 16
Special: A ship equipped with a piercing ram also grapples the target.
The pilot of the ship is able to perform special maneuvers to make the vessel do amazing things, but these maneuvers require an Athletics check to perform successfully. The DCs to perform these maneuvers come from the Difficulty Class and Damage By Level table found on Page 42 of the DMG. Performing a stunt is a full-round action; it requires considerable concentration to pull off successfully.
You maneuver the ship to avoid colliding with something.
Obstacle To Avoid
Debris Field (1x1)
Debris Field (2x2)
Debris Field (3x3)
Moderate + 2
Hard + 2
Success: You avoid the obstacle and shift the vehicle one square.
Fail: You collide with the object taking damage as if rammed.
You make a radical turn, drastically changing the ship's heading, but come to a stop in the process.
Hard + 4
Success: The ship moves forward a number of squares equal to the distance traveled the previous round, stops, and then changes heading. Anyone standing must make an Easy Acrobatics check to avoid being knocked prone.
Fail: You fail to rapidly turn. Make a Moderate Athletics check to avoid becoming Out of Control.
You quickly accelerate, performing a double-move with a single move action.
Difficulty: Moderate + 2
Success: You're able to take two drive actions for the cost of one.
Fail: You're unable to dash.
Special: You can only perform this stunt once per round.
You attempt to free your ship from a grab.
Difficulty: Special. Make an Athletics check versus the grappling ship's Fortitude.
Success: You end the grab, and can shift the ship one square as part of the stunt.
Fail: Your ship remains grabbed; you cannot perform move actions and your ship travels in the direction and speed of the grappling ship.
You mislead another ship so that it has a harder time dodging your ship's attacks.
Diffculty: Special. The target ship's pilot makes an Insight check to see through the pilot's feint. The feint succeeds if the pilot's feint check exceeds the target ship's Insight check.
Success: Your ship gains combat advantage until the end of your next turn.
Fail: The target ship sees through your trickery.
Special: Feint uses the pilot's Bluff or Intimidate skill instead of Athletics. If using Intimidate, the feint succeeds if the Intimidate check exceeds the target's Will.
You pull along side a vessel, locking the two ships together.
Difficulty: Special. Make an Athletics check versus the target ship's Reflex.
Success: You shift into an adjacent square to the target ship and it becomes grabbed (its speed matches yours, and it cannot perform move actions until it successfully performs an Escape).
Fail: You fail to grapple the target ship and instead, you collide with it, taking damage as if rammed.
Special: You must be within one ship square to grapple an enemy ship. You may attempt to tow the grappled ship by making a Moderate Athletics check. If successful, you may move up to half your speed per move action, and you perform turns in a weight class equal to the combined weight of your ship and the grappled ship. If you fail, then the grappled ship automatically escapes.
You stop the ship rapidly.
Success: Your ship shifts forward one square, and stops. Anyone standing must make a Moderate Acrobatics check to avoid being knocked prone.
Fail: You fail to rapidly slow down. Make a Moderate Athletics check to avoid becoming Out of Control.
Special: You can only perform this stunt once per round.
You overcome inertia and rapidly turn the ship
Difficulty: Hard + 2
Success: Your ship makes a 45 degree turn without performing the required drive actions beforehand. Anyone standing must make an Easy Acrobatics check to avoid being knocked prone.
Fail: You fail to turn. Make a Moderate Athletics check to avoid becoming Out of Control.
You shift the ship diagonally in its direction of travel without turning.
Difficulty: Moderate + 2
Success: You shift the ship along a forward diagonal a number of squares up to its Speed.
Fail: You fail to sideslip. Make a Moderate Athletics check to avoid becoming Out of Control.
You shift your ship and collide with an object, possibly forcing the pilot to lose control.
Difficulty: Moderate + 2
Success: You ram the object for half ram damage, and if piloted, the target's pilot must make a Moderate +2 Athletics check to avoid going Out of Control.
Fail: You ram the object for full damage.
Special: If your ship is heavier than the target ship and you succeed in the sideswipe, the target's pilot receives a -2 penalty to his/her Athletics check. If your ship is lighter, the target ship's pilot receives a +2 bonus to his/her Athletics check.
You exit the fray and try to jump to spelljamming speed.
Difficulty: Hard + 4
Success: You may perform up to four move actions, and attempt to jump to spelljamming speed (Moderate Arcana check)
Fail: You fail to withdraw. Make a Hard Athletics check to avoid going Out of Control.
Special: You may only perform this stunt once per round. Ships with aether drives require an engineer to make the Arcana check.