Spelljammer

Spelljammers are magical vessels that can traverse through deep space or the Frozen Sea. They can come in many forms but all require a spelljamming helm to operate.
Spelljamming helms
Spelljamming helms are the central setting concept that allows interplanetary and interstellar space travel for vessels otherwise not spaceworthy, in the form of a helm. Any spellcaster may sit on a spelljammer helm to move the ship. The mysterious race known as the Arcane is the sole manufacturer and distributor of spelljamming helms