Superior Ship Upgrades

Some vessels possess extraordinary abilities, whether due to magic of superior artisanship. The upgrades below can replace a ship's existing components or provide a new element to augment a ship's ability.
Adding an upgrade costs 15,000 GP and requires 1d4 weeks of work. During that time, the ship must remain in port, if the ship leaves, the work must start over, but you don't need to pay the gold piece cost a second time.

Hull Upgrades

Any ship with a hull can gain one of the following upgrades.
Death Vessel
Crafted with materials harvested from Mabar manifest zones, this upgrade grants a ship an aura of dread. As a action, the ship can create a pulse of horrific energy. Every creature that is an enemy of the ship is on board or within 210 feet of it must make a DC 14 Wisdom saving throw. On a failed save, a creature is frightened of the ship for 1 minute. On a successful save, the creature is immune to this ability for 24 hours. Once this ability is used, it can't be used again until 1d4 hours have passed.
Frost-Locked Hull
This upgrade replaces a ship's hull with a supernatural ice drawn from the plane of Risia. The hull and the other components of the ship are immune to cold damage but vulnerable to fire damage. The ship can also move at its normal speed over ice of any thickness, floating on the ice at the same depth as it would in water.
Living Vessel
This vessel's hull was crafted in Thelanis under the direction of master eladrin shipwrights. It is a living plant, drawing sustenance from the water and sunlight. Vines covered in thick leaves hang over its side, and the wood runs with fresh sap when damaged. The ship gains a +2 bonus to all Constitution checks or saving throws. As long as the ship has at least 1 hit point, it regains 10 hit points every minute.
Reinforced Hull
A master shipwright can use superior materials and clever design to make a ship's hull more resilient. Such reinforcement doubles the hull's hit point maximum.
Vigilant Watch
A row of crystal orbs, each filled with a viscous liquid and a beholder's eyeball, is mounted along this ship's hull. Invisible creatures are visible while on the ship or within 120 feet of it.

Weapon Upgrades

The following upgrades can apply to any weapon mounted aboard a ship. A component can gain the benefits of one upgrade, or two upgrades if one of the upgrades is Arcane Artillery.
Arcane Artillery
Using methods similar to those used to produce magic weapons, a skilled spellcaster imbues a ship's weapon with destructive energy. This weapon gains a +2 bonus to attack and damage roles, and its attacks count as magical.
Concussive Rounds
Enhanced by abjuration magic, this weapon's attacks burst with raucous noise capable of distracting and disorienting enemy crews. If this weapon hits a vehicle's hull, that vehicles speed is decreased by 2d10 feet until the start of the attacker's next turn.
Explosive Rounds
Drawing on powerful evocation magic, this weapon's attack are imbued with unstable energy that explodes in a fiery blast. When this weapon hits, it deals an extra 2d6 fire damage.
Grasping Rounds
This weapon creates spectral chains that trail after its shots, restraining enemy vessels in their grasp. When this weapon hits a ship, that vehicle must succeed on a DC 14 Strength saving throw or it cant move away from the attacker. As an action, the attacking ship can end this effect, and the target can end it by taking an action and succeeding on a DC 14 Strength check.

Figurehead Upgrades

While figureheads are usually purely decorative, they might be magically treated to produce extraordinary effects. A ship can receive one figurehead upgrade.
Guardian Figurehead
This figurehead depicts an armored knight. As an action, the ship can activate this item, causing it to animate as an iron golem. The golem acts on the ship's turn when the captain uses one of the ship's actions. The golem remains animated for 1 minute. At the end of that time, it teleports back to its position as a figurehead. Once a ship uses this action, it can't use it again for 24 hours.
Red Dragon Figurehead
This figurehead depicts a red dragon rearing to strike, its mouth open. As an action, the ship can activate this item to create a 60-foot cone of fire that originates from the figurehead. Each creature and object in the cone must make a DC 12 Dexterity saving throw, taking 21 (6d6) fire damage on a failed save, or half as much on a successful one. Once a ship uses this action, it can't use it again for 24 hours.
Storm Giant Figurehead
This figurehead depicts a storm giant clutching a thunderbolt. As an action, the ship can activate this item to create a 60-foot cone that originates from the figurehead. Each creature in the cone must make a DC 12 Constitution saving throw, taking 14 (4d6) thunder damage on a failed save, or half as much damage on a successful one. A creature that fails its saving throw is also pushed 10 feet away from the figurehead. Once a ship uses this action, it can't use it again for 1 minute.

Miscellaneous Upgrades

Bones of Endless Toil
The bones of ancient, mysterious creatures festoon the ship. Potent runes crawl across these remains, emitting a sickly green radiance. When a humanoid dies aboard the ship, that creature must make a DC 12 Wisdom saving throw. On a successful save, it dies as normal. If it fails, it immediately rises as a zombie obedient to the ship's captain. The zombie gains working knowledge of the ship, allowing it to serve as a member of the crew. A number of creatures equal to the ship's creature capacity can be animated in this manner at any given time.
Smuggler's Banner
This flag is meant to be flown from a ship's mast. Its powerful magic causes it to appear as a flag or banner displaying the symbol of a group, captain, or realm friendly to the viewer. Multiple viewers might see different flags or crests.
The banner's true power is its ability to aid a ship in making rapid escapes. As an action, the ship and all friendly creatures aboard it teleport up to 3 miles to a known destination of the captain's choice. Hostile creatures aboard the ship don't move with the ship and fall into the water it once occupied. Once this item is used to teleport, it can't teleport in this way again for 2d6 days.