What is the penalty for an interference in surfing?
A · Advanced · Priority and interference · 1 of 4The surfer loses part of their heat total. Without priority in play, their second-best wave is halved. Where priority applied, their second-best wave counts as zero. In the last five minutes of a heat at the major events, it is their best wave that counts as zero. Two interferences in a heat send the surfer out of the water.
How it works
- Penalty 1: "The value of the interfering Surfer's second highest scoring Ride will be halved."
- Penalty 2: "The interfering Surfer's second highest scoring Ride will tally as a zero."
- Penalty 3: "The interfering Surfer's highest scoring Ride will tally as a zero."
- Which applies: penalty 1 in non-priority situations and penalty 2 in priority situations.
- The last five minutes: at the World Surfing Games and Olympic-related events, an interference that stops a potential scoring ride in the final five minutes brings penalty 3.
- If intentional then: disqualification from the heat.
- The wave itself: the ride on which the surfer interfered scores zero.
- Priority gone: a surfer who incurs an interference loses priority.
- Two in a heat: the surfer "must immediately leave the Competition Area".
- Two without priority: penalty 1 on both the highest and second-highest rides.
- Two with priority: disqualification from the heat.
- An extra wave: in non-priority heats the surfer interfered with may ride one more wave than the limit.
The glossary has the interference penalties entry, the interference entry, the priority entry, the score, the heat and the combo entry.
Tricky cases
A surfer with waves of 8.0 and 6.0 commits a priority interference. What is their total now?
8.0. The second-highest ride tallies as zero.
The same surfer, but in a non-priority situation. What is the total?
11.0. The second-highest ride is halved, from 6.0 to 3.0.
A surfer leading with two minutes left drops in on their rival's last wave at an Olympic qualifier. What happens?
Their highest-scoring ride counts as zero. If the judges find it was intentional, they are disqualified from the heat.
Does the surfer who was interfered with get anything?
In non-priority heats, an additional wave beyond the limit within the time. In a double interference neither surfer gets one.
Why the rule exists
Because a heat total is two waves, removing or halving one of them is usually decisive: the offender in effect competes on a single wave. The harsher penalty late in a heat closes a loophole. Without it, a surfer who was ahead could spoil a rival's last wave and accept a lesser penalty.
Where it differs
| Where | What changes | Source |
|---|---|---|
| Non-priority | Second-best ride halved | ISA, Interference Penalties a; b |
| Priority | Second-best ride zero | ISA, Interference Penalties a; c |
| Final five minutes, World Surfing Games and Olympic-related events | Best ride zero | ISA, Interference Penalties d |
| Tandem | Second-best score halved | ISA, Judging Criteria iv |
From the rule book
International Surfing Association, Rulebook and Contest Administration Manual (30 July 2026), Interference Rules and Priority: Priority System 1 and Interference Penalties. Checked 14 October 2026. Official document: ISA Rule Book, July 2026 (PDF).