Mariner class series

The Mariner class series is the default class series available to the Mercury Adept Piers. Piers becomes this class series when he either has only Mercury Djinn set or no Djinn at all. This class series is unique to Piers; Mia, the other Mercury Adept, is a healer rather than a warrior and has her own default class series, the Water Seer class series.

Psynergy Setup
The Mariner class begins with the Diamond Dust Psynergy Technique, the Frost Psynergy series, the Cool Psynergy series, the Ply Psynergy series, and the Cure Poison, Restore, and Break Psynergies. In the Privateer class (the class Piers is actually in when he first joins your party, as he carries two Mercury Djinn with him), the Avoid Psynergy is gained. The Commander class retains this Psynergy setup, and in the Captain Class, Diamond Dust is upgraded into the Diamond Berg Psynergy Technique. The Admiral class retains this Psynergy setup.

It is widely argued that the Mariner Class series is better for battle than the Water Seer Class series, while the latter is better at healing.