For battles with front and back hero rows. Do not apply the same figures directly to march combat.
Who are the Mariner heroes?
There are five Mariner heroes, all SSR. The front and back rows below are example positions.
Shark
Reduces the damage it takes and raises HP and Defense for every front-row ally.
Ragnar
Every few attacks it slashes a wider area, and it raises its own Attack and Defense.
Knotty
Attacks with area explosions. Its skill widens the blast and raises the damage, and it boosts its own Attack.
Undine
Attacks while raising auto attack damage for the whole team and Attack for back-row allies.
Dave
Keeps up a steady water spray and lowers enemy Attack and Defense.
What changes when you add Mariners?
For the same-faction bonus, a Mariner counts as any faction, so in practice it joins the largest faction in your lineup. Three Aeronauts and two Mariners are counted as five Aeronauts for the HP bonus.
Each deployed Mariner gives every hero 2% more Final Attack and 2% less Final Health. Two Mariners mean +4% Attack and −4% Health.
Mariners stay out of faction counters. They neither deal nor take the 20% counter damage, and they're left out of the extra counter bonus. They also have no Faction Enhancement branch or Star Points.
Faction Enhancement: where should your Star Points go first?
5 Aeronauts or 3 Aeronauts + 2 Mariners?
Swap two Aeronauts for Mariners and the HP bonus drops from 25% to 21% and the 5% extra counter bonus disappears, while Attack goes up 4%. Only the three Aeronauts still count for counters.
| 5 Aeronauts | 3 Aeronauts + 2 Mariners | |
|---|---|---|
| Same-faction HP bonus | 25% | 21% |
| Mariner attack bonus | None | +4% |
| Extra counter bonus | 5% | None |
| Heroes counted for counters | 5 | 3 |
So when is a Mariner worth it?
The bonus numbers alone won't settle it, because HP, Attack and counter percentages can't be added up into one damage figure. Start with whether a Mariner fills a role your lineup is missing.
If your front row can't hold, Shark raises HP and Defense for every front-row ally. If you run several back-row attackers, Undine adds back-row Attack and auto attack damage for the team. If five heroes of one faction already cover the roles you need, there's little reason to swap.
One lineup with two Mariners puts Shark and Tony in the front row and Undine, Alita and Kiki in the back.