Traveling Rules in the Skies

The following rules are adapted from Wizards of the Coast's Ghost of Saltmarsh.

Travel in the Skies:

It’s not just pirates and sky monsters that make journeys between sky islands so treacherous. Foul weather, nautical accidents, infested food, illness, and worse all conspire to send even the most capable crews to their graves. The following rules help adjudicate travel in the skies, specifically voyages of an hour or more. This material builds on the travel rules in the Player’s Handbook and the Dungeon Master’s Guide.

Travel Pace

Ships travel at a speed given in their stat blocks. Unlike with land travel, ships can’t choose to move at a faster pace, though they can choose to go slower.
If a ship’s mode of movement takes damage, it might be slowed. For every decrease of 10 feet in speed, reduce the ship’s travel pace by 1.5 km per hour and 38.5 miles per day.
Even ships that do not use sails for their primary mode of movement are still subject to the whims of the Skies. Moving against the wind halves the travel pace of the ship, while moving with it grants a small boost in speed (multiply the travel pace by 1.2 for as long the ship moves with the wind). At any point, the Dungeon Master may roll 1d8 and consult the following table to determine winds direction (either at the beginning of the day or any other time).

Roll	Direction
1	North
2	North East
3	East
4	South East
5	South
6	South West
7	West
8	Northwest

Ship Rations and Cooking:

Crews are ravenous, as workmen and women require hearty meals to support their work intensive lifestyle. Ship rations represent an easy way to conceptualize and keep track of this without things getting too complicated. Ship rations represent both food and water, the essentials to keep living beings going. For the sake of simplicity, a single crewmate consumes roughly 1.5 kg of food every day. Ship rations are bought in bulk at ports across the Sky, or otherwise scavenged during voyages to extend the ship's food stocks. A bundle of 10 kg of rations can be purchased for 10 rarity 4 Slivers. For salvaging, say from hunting or raiding another ship's stores, the DM must determine the amount of salvage using the following table:

Find	Amount
Small Find (Hunting small game, light foraging, etc)	1-5 kg of ship rations
Medium Find (Hunting medium game, heavy foraging, claiming supplies)	10-20 kg of ship rations
Huge Find (Hunting huge game, raiding another ship's pantry)	50-75 kg of ship rations

Activity While Traveling

The activities available to a ship’s crew and passengers are a bit different from the options available to a group traveling by land. Refer to “Activity While Traveling” in chapter 8 of the Player’s Handbook for more information on some of the topics discussed below.
A number of activities are restricted to certain officers, unless the DM rules otherwise. For example, a DM might allow a bard to engage in the Raise Morale activity by playing bawdy songs on deck to lift the crew’s spirits.
The party’s pace has no effect on the activities they can engage in while traveling by ship.

Draw a Map

A ship’s captain often undertakes this activity, producing a map of the ship’s progress and helps the crew get back on course if they get lost. No ability check is required.

Forage

The character watch the Skies with Harpoon Crossbows, keeping an eye out for sources of food, making a Wisdom (Survival) check when the DM calls for it. Refer to the ship rations rules from earlier in this article for more information.

Raise Morale (Usually First Mate)

The first mate can manage the crew’s time to grant extended breaks, provide instruction, and generally improve the quality of life on the ship. Once every 24 hours, if the crew’s quality score is 3 or lower, the first mate can make a DC 15 Charisma (Persuasion) check. On a successful check, the crew’s quality score increases by 1.

Navigate (Usually Quartermaster)

Once per day, the quartermaster must make a DC 10 Wisdom check to ensure the ship is on a correct course, using various navigational equipment and techniques (such as a maritime clock, a sextant, and the position of the stars). Failure causes the ship to become briefly lost, veering 1d20 kilometers off course (which is then added to the total amount of kilometers needed to reach the destination). Complicating factors such as bad weather, unfamiliar Skies, and a lack of proper navigational tools raise the DC by +5 for each complicating factor. 

Noticing Threats

Use the passive Wisdom (Perception) score of the player characters or the crew to determine whether anyone on the ship notices a hidden threat. The crew has a passive Wisdom (Perception) score equal to 10 + the crew’s quality score. The DM might decide that a threat can be noticed only by characters in a specific area of the ship. For example, only characters below deck might have a chance to hear or spot a creature hiding on board.

Repair (Usually Bosun)

At the end of the day, the ship’s bosun can make a Strength check using carpenter's tools, provided they have materials necessary for the repair. On a 15 or higher, each damaged component regains hit points equal to 1d6 + the crew’s quality score (minimum of 1 hit point). A component other than the hull that had 0 hit points becomes functional again.

Stealth (Usually Captain)

The ship’s captain can engage in this activity only if the weather conditions restrict visibility, such as in heavy fog. The ship makes a Dexterity check with a bonus equal to the crew’s quality score to determine if it can hide.

Hazards

Sky travel is an innately dangerous proposition. A storm on land might bog down a caravan, delaying its trip by a few days, while in the Skies a storm can split a ship in two and send everyone aboard to their doom. The close quarters of life aboard a ship leads to short tempers and brawls, while a few Slime Balls that sneak aboard can spoil supplies.
At the beginning of every day of travel roll 1d6. On a 6, a hazard occurs. If your instead moving in weeks (4 days), roll a d4. On a 4, a hazard occurs. See the Sky Hazards to determine what it is and the severity.

Group Checks

To determine how a ship fares against these hazards, each threat requires the ship’s officers and crew to make a special group check (see chapter 7 of the Player’s Handbook for how group checks work). The description of a hazard specifies which officers can roll to contribute to the group check. That description also states what ability check an officer makes. Even if the officers make different ability checks, their successes and failures contribute to the one group check.
Additionally, all the non-officer members of the crew make a single check, a d20 roll modified by the crew’s quality. The success or failure of all these checks — both the officers and the crew — determines the result of the group check.
While each hazard lists the officers assigned to participate in a group check, anyone can attempt an officer’s check in a pinch, with two exceptions: First, only the captain can make checks associated with the captain’s role; no one else can take the captain’s place. Second, only one character can attempt an officer’s check; they can’t receive help.
Once all the checks related to the group check have been rolled, the ship’s success or failure is determined. Hazards offer four levels of success or failure determined by the results of the ship’s group check. A total success or a total failure occurs when every roll in the group check is a success or a failure, respectively.
For hazards in the Skies see the Sky Hazards for more information.