Once the heroes have finished making their preparations, they can board the ship and set sail into the Cerulean Gulf.

The First Constellation#

From the mainland, the Antikythera (appendix C) can be used to navigate to any of the islands in the Cerulean Gulf. The heroes should choose one of the first 9 constellations and calibrate the Antikythera for their destination.

It’s not immediately clear which constellations lead to which islands, so it may require the heroes to guess. However, there are a few well-known islands that the sailors are familiar with and can identify the constellation that is associated with it. Some player backgrounds are also familiar with certain islands and should be able to identify the constellation that is associated with that island. Refer to the Constellations and Destinations table for details.

Navigating the Oceans#

The Cerulean Gulf and the Forgotten Sea are the domains of Sydon, Lord of Storms. He churns the oceans with his magic, making the waters treacherous for mortal sailors. Magical means are required to navigate these vast bodies of water. Powerful ocean currents prevent ships from approaching the islands without knowing their exact whereabouts. This is why most merchant ships remain close to the coast. The only way to successfully navigate the oceans is to use the magical compass that Vallus gave to the party: the Antikythera (appendix C).

The Antikythera#

This enchanted machine is a complex construct that serves as a magical compass. It attunes itself to the constellations in the night sky in order to provide accurate directions to the islands scattered around Thylea.

Choosing Destinations. The Antikythera must be used on dry land to determine a destination, as the constant movement of the ocean makes it impossible to calibrate the device properly. Every island is associated with a specific constellation. When the Antikythera is calibrated to the proper constellation, it will show the precise path that can be used to reach the island associated with that constellation.

Missing Gearwheel. There is a gear missing from the Antikythera that can be found in the Great Library (area Y17) on the Island of Yonder. When this gear has been returned to the device, the islands in the Forgotten Sea will become available.

Travel Times and Encounters. The winds and waters of Thylea are strange and unpredictable. Once the party chooses a destination with the Antikythera, it takes 3 days of sailing to get there. The standard travel time between any two islands is always 3 days, no matter how close they appear on the map. Returning to the mainland also requires 3 days.

Faster Travel#

Travel times can be shortened by one day by using a Control Weather spell, or by sacrificing 100 GP worth of livestock to Sydon to ensure strong, favorable winds. Gust of Wind can also be used for this purpose, but the caster must maintain the spell for an entire day and this causes one level of exhaustion. Travel times cannot be reduced to less than 2 days.

Fifty Oarsmen#

The Ultros requires at least fifty oarsmen to move at its normal pace. If the crew roster of the ship falls below fifty oarsmen, then the travel time between landmasses is increased by one day.

Sea Encounters#

Each time the party sets sail for a new island, roll on the Random Sea Encounter table later in this chapter. Once an encounter has been resolved, the heroes should have smooth sailing until they arrive at the next island. Sea encounters should not be repeated.