What is a base mark in artistic swimming, and why does it sink a routine's score?
I · Intermediate · Judging and results · 3 of 7A base mark is the lowest difficulty value an element can have. Coaches declare every element and its difficulty beforehand on a coach card. If the swimmers leave out or change any part of a declared element, the technical controllers cut that element to its base mark, and its execution marks are multiplied by that small number.
How it works
- The card: "Coach Cards of declared difficulty for each event entered must be submitted electronically."
- Changes: allowed until 18:00 local time on the day before the session. "No changes are possible after this deadline."
- Difficulty: the sum of the values of an element's components and bonuses, plus its base mark.
- The base mark: "the minimum Degree of Difficulty that will be applied if one (1) or more components of the element is not performed or is not in conformance to what is declared in the Coach Card".
- Who decides: one difficulty technical controller and two assistants follow the card in real time.
- Video: they may use one slow-motion review for each element or transition they question.
- Two of three: for a base mark to be applied, two of the three controllers must agree.
- Other causes: a base mark is also applied to a repeated acrobatic, to a hybrid that goes beyond the limits on one family or one technique, and to a reserved acrobatic code used by a federation that does not own it.
The glossary has the coach card, the base mark, the degree of difficulty and the technical controllers.
Tricky cases
The swimmers perform one rotation fewer than declared. Does the element lose only that part?
No. If one or more components are not performed as declared, the whole element goes to its base mark.
Can a coach lower the difficulty on the morning of the final?
No. Changes close at 18:00 the day before the session, or at a time World Aquatics sets.
Is a base mark a penalty taken off the score?
No. It replaces the element's difficulty. The judges' execution marks are still counted and are multiplied by the base mark.
Can a coach challenge a base mark?
It depends on the protest rules. The Referee adjudicates protests about the session, and the procedure in Part One of the regulations was not checked for this page.
Why the rule exists
If a team could declare a hard element, perform an easier one and keep the higher value, declared difficulty would mean nothing. The base mark makes over-declaring a gamble: the element is worth its full value or close to nothing.
Where it differs
| Where | What changes | Source |
|---|---|---|
| Free elements: hybrids and acrobatics | Cut to the base mark | AS 18.1.7 and the same clause for each routine |
| Technical required elements | A zero difficulty, not a base mark | AS 18.1.9 |
| Team technical routine | The one team acrobatic is limited to a difficulty of 3.0 | AS 18.4.15 |
| Youth and 12 and under teams | Safety limits on acrobatic difficulty | AS 18.8.12; AS 18.8.13 |
From the rule book
World Aquatics, Competition Regulations, Part Seven: Artistic Swimming Rules (in force as from 1 January 2025), Articles 6.3, 16.1, 16.1.1, 17.2, 18.1.7, 18.2.15, 18.2.16, 18.8.14 and 19.1. Checked 14 October 2026. Official document: World Aquatics Competition Regulations (PDF).