Stats of a Longship

Ballista Bolt. Ranged Weapon Attack: +6 to hit, range 120/480 ft., one target. Hit: 16 (3d10) piercing damage.

Dolphin Figurehead:

This Thassa-blessed figurehead depicting a pod of dolphins has the power to summon nyxborn reflections of the same creatures from their dance around the ship’s bow to aid the crew when threatened. As an action the ship can cast the conjure animals spell to summon eight Nyxborn dolphins, which act after the ship in combat, fighting to protect the ship and its crew. Roll Nyxborn properties for the dolphins when they are summoned (MOoT, Chapter 6, Nyxborn Creatures). Once a ship uses this action, it can’t do so again until the next dawn.

Nyx-wood Hull:

Cutting lumber from a nyx-touched forest is a difficult prospect—one likely to anger both Nylea and Karametra— but a hull of Nyx-touched wood grants a vessel incredible properties. A ship with a Nyx-wood hull sheds dim light for 15 feet, and the vessel has advantage on saving throws against spells and other magical effects.

Nyx-fleece Sails:

Many seek the fleece of a nyxborn ram for its healing properties, but a sail woven from the wool of a Nyx-fleece is said to improve the health of an entire ship’s crew, making rations stay fresh for longer, staving off minor illnesses, and aiding the recovery of injuries. Sails such as these may be gifted by Karametra to her champions. At the start of each week, if the crew's quality score is lower than +3, it increases by 1. Characters that finish a short rest aboard a ship with Nyx-fleece sails and roll a 1 on any hit dice they expend can reroll that die, and must use the new roll.