Yal graduated from Starfleet Academy in 2354 with honors in probability and temporal mechanics. He served on many starships during his career, including two freighters in 2357 and a small Oberth-class vessel, the USS Gandhi for five years as a science officer.
In 2368, Commander Chakotay of the USS Livingston resigned his commission, which left the Livingston without a first officer. Yal had held the rank of lieutenant for five years and received a promotion to Lieutenant Commander. He became the new first officer in 2369 and served as XO until his death in 2382, while trying to save a convoy of Kellodian ships from destruction at the hand of the Cardassians. The Livingston was decommissioned the same year.