There are numerous underwater hockey formations. I will not explain how each formation works, but I will attempt to explain what is meant by the 3-1-2 formation as opposed to the 1-3-2 formation.
Naming
X-Y-Z here means X forwards, Y mids, and Z backs. A-B means A forwards and B backs, no mids.
Atlantis counts offensive-leaning players first and defensive players last, with hybrid roles in the middle. For common shapes the numbers often match. If a coach says “2-3-1,” ask whether the middle three are mids or wings/centre — labels differ by club.
No formation is right for every situation, nor is there any formation which is wrong for any situation. The key is for each player playing his or her position well. The key to picking a formation is knowing your team’s strengths and your opponent’s weaknesses.
Comparison
| Formation | Shape | Play style | Suits | Watch for |
|---|---|---|---|---|
| 3-3 | 3F / 3B | Wide wall pressure, cycling, side switch | Clear roles; wall work | Only two lines; backs and wings swim a lot |
| 2-3-1 | 2F / 3 mid / 1B | Pressure and overlaps; outnumber around the puck | Fit teams that rotate support quickly | Breaks if support disconnects; high workload |
| 2-2-2 | 2F / 2 mid / 2B | Open-water possession through the middle | Possession practice | Soft wall pressure; central turnovers hurt |
| 1-3-2 | 1F / 3 mid / 2B | Containment; score when the lone forward finds space | Disciplined mid lines | Few forward options; swings harder to cut |
| 3-2-1 | 3F / 2 half-back / 1 full-back | Width and space; fewer wall scrapes | Teams that swim and pass wide | Gaps between layers if spacing opens |
| 2-1-2-1 | 2F / 1C / 2 half-back / 1 full-back | Vertical layers; wall cycling with support behind | Wall-oriented systems | Wide pools and fast side switches |
Same numbers do not mean the same game: two 3-3s can play completely different styles.
The 3-3
The most common formation for beginners to learn is the 3-3; three forwards and three backs. Some advanced US teams play a 2-3-1. Positioning and scenario chapters below use the 3-3.
In a 3-3 formation, I will refer to the three forwards as the Left Forward, Center Forward, and Right Forward. The three backs will be Left Back, Center or Swing Back, and Right Back.
In other countries, the same formations can have slightly different names. In Canada, for example, the three forwards would be Left Wing, Center, and Right Wing, and the three backs would be Left Pivot, Swing, and Right Pivot.
Further Reading
Positions, Forwards in the 3-3, Backs in the 3-3. Diagrams: Atlantis — Formations.