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Swimming, water polo, diving and artistic swimming

Four sports draw a pool: sport: "swimming" (the competition pool, in lanes), "waterpolo" (the field of play), "diving" (the well, with its springboards and platforms) and "artisticswimming" (the routine area). Each is drawn to scale from World Aquatics' Competition Regulations (in force as from February 2026), which is where the Facilities Rules (FR 2 to FR 8 of the 2017 to 2025 editions) now sit as Article 15 of Part Two, Article 15 of Part Four, Articles 20 and 21 of Part Six and Article 12 of Part Seven (in the edition of 25 June 2025 they were Articles 16, 13, 18 and 27). Every figure is cited in sources.md, and each says where the rules give no figure and the drawing's is ours. The pool is drawn wide (the start at the left; a tall drawing turns it a quarter, with the words still upright), in metres, the unit the rules print.

import { drawKyogijo } from "@johnmorrisdotca/kyogijo-stadiums";

const wide = drawKyogijo({ sport: "swimming", id: "p" });
const tall = drawKyogijo({ sport: "swimming", orientation: "portrait", id: "p" });
console.log(wide.match(/viewBox="([^"]*)"/)?.[1], "|", tall.match(/viewBox="([^"]*)"/)?.[1]);
// -8.2 -8.2 180.45 98.43 | 0 0 98.43 180.45

All four take a pool option for the look, layers, range, landmarks, a score of two teams (a dual meet, a water polo match), every renderer, and the usual themes and looks. The pools have no league: World Aquatics has one rulebook.

The swimming pool#

The default is the pool of the Olympic Games: 50 m between the touch panels, eight lanes of 2.5 m with a space of 2.5 m outside the first and the last (Part Two Article 15.6.1), 25 m wide. pool.course: "short" is the 25 m pool; pool.lanes is 1 to 10.

import { swimPlan } from "@johnmorrisdotca/kyogijo-stadiums";

const ten = swimPlan({ sport: "swimming", pool: { lanes: 10 } });
console.log(ten.width, ten.lanes.map((lane) => lane.number).join());
console.log(ten.ropes.map((rope) => rope.colour[0]).join(""));
// 25 9,8,7,6,5,4,3,2,1,0
// gbbbyyybbbg

The blocks, the flags and the false start rope make a competition pool. pool.kind: "warm-up" leaves them out with the touch panels: the same lanes and ropes in a pool for warming up. The rules set no size for a swimming warm-up pool, so it is whatever course and lanes say. blocks, pads, flags and falseStart switch each one on or off.

Lines are drawn a little thicker than they are painted, as the other surfaces' are, and the small fixtures (blocks, flags, standards) about half as large again. The ropes are rows of round floats drawn as dots in one path each, so a pool with nine ropes stays under 19 kB with its stylesheet.

The water and the deck#

The rules say nothing of how water or a deck look, so these are ours. pool.look is flat (the default: one clean colour), water (a net of light on the floor, in a repeating tile, with the water a little darker towards the middle of the pool) or tiled (the same, with the tiles of the floor showing through). pool.deck is plain or tiled. The light is a few soft closed curves made from a seed (pool.seed, 1 by default), with no random number: the same seed draws the same light, and a tile is one pattern that every pool of a drawing reuses.

import { drawKyogijo } from "@johnmorrisdotca/kyogijo-stadiums";

const flat = drawKyogijo({ sport: "swimming", id: "l" });
const lit = drawKyogijo({ sport: "swimming", id: "l", pool: { look: "tiled", deck: "tiled", seed: 7 } });
console.log(flat.includes("<pattern"), lit.match(/<pattern/g)?.length);
console.log(lit === drawKyogijo({ sport: "swimming", id: "l", pool: { look: "tiled", deck: "tiled", seed: 7 } }));
// false 3
// true

The scenes and the other renderers read the patterns, the gradients and the dashes that make the floats; a pool as a PNG is the same picture. The colours of the water, deck, ropes, panels and blocks are custom properties (--ky-surface, --ky-apron, --ky-pg, --ky-pb, --ky-py, --ky-pr, --ky-pw for the ropes' green, blue, yellow, red and white), light and dark, and every named look paints a pool in its own palette; featureColors names water, apron, gutter, lane-lines, lane-ropes, rope-red, touch-pads, starting-blocks, backstroke-flags and false-start-rope.

A side section#

pool.section: true draws a section along the pool under the plan, on the same scale along the pool: the water and its depth, the blocks and touch panels at the walls, a pennant for the backstroke flags 5 m from each end, a dot and a pole for the false start rope at 15 m, a lane rope at the surface, the lane marking on the floor, the depth as a dimension, and the least depth the rules ask near a wall with blocks (1.35 m, a dashed line from 1 to 6 m). The depth is 2.5 m for a 50 m pool and 2.0 m for a 25 m one, or section: { depth }. The height is exaggerated (2.5 times by default, exaggerate): a pool 50 m long and 2.5 m deep is a sliver otherwise, and the description says the section's depth.

The lanes of a race#

pool.race puts a race on the pool: the swimmers in their lanes with their names and flags at the starting end, and, once the race is swum, each place (a medal for the first three), time, reaction time and the splits at the turning end.

import { swimPlan } from "@johnmorrisdotca/kyogijo-stadiums";

const pool = {
  race: {
    event: "Men's 100 m freestyle, final",
    distance: 100,
    swimmers: [
      { lane: 4, name: "A. Swimmer", abbr: "AUR", splits: [25.1, 52.4], reaction: 0.64 },
      { lane: 5, name: "B. Swimmer", abbr: "CAL", splits: [25.6, 52.9], reaction: 0.7 },
      { lane: 3, name: "C. Swimmer", abbr: "BOR", status: "dq" as const, time: 52.0 },
    ],
  },
};
const rows = swimPlan({ sport: "swimming", pool }).race!.rows;
console.log(rows.map((row) => `lane ${row.lane}: ${row.timeText}, place ${row.place}`).join("; "));
// lane 5: 52.90, place 2; lane 4: 52.40, place 1; lane 3: 52.00, place undefined

The race itself is { event, distance, swimmers, show, pace, splitEvery }. The distance comes from the splits when it is missing. show takes names, flags, results, reaction, splits, medals and seeds, each false to leave out. The rows go down the page in the order of the lanes, so lane 8 is at the top of a wide drawing; the names and times of a tall drawing lie along the lanes, and the numbers in the discs stay upright.

pace: true draws the split pace bars: each lane as the whole race laid out flat (a 200 m race in a 50 m pool is swum along the lane and back, and drawn from the start at the left to the finish at the right), each split a bar as long as its share of the race, in a colour from the field's slowest pace (dark) to its fastest (bright), with the split's time on it unless pace: { labels: false }, under a ruler of the distances. splitsChart wraps it with a title, a summary and a table.

The description says it all in words: the event, then each lane (Lane 4: Name (AUR), place 1, gold medal, time 1:46.12, reaction time 0.64, splits ...), and what the bars show.

A race replay#

raceTimeline (from @johnmorrisdotca/kyogijo-stadiums/replay) turns a race's splits into a replay timeline: each swimmer goes down the first length and back the next at the speed of each split, in a straight line between the splits, and is on the block until the reaction time. The timeline is in the pool's frame (swimming: metres from the middle of the water, x towards the turning end, y up the page, so lane 1 is below lane 8), and its events are the start, the turns at the walls and the finishes, each with the swimmer's name and the time.

import { drawFrame, raceTimeline } from "@johnmorrisdotca/kyogijo-stadiums/replay";

const pool = { race: { distance: 100, swimmers: [{ lane: 4, name: "A. Swimmer", splits: [25.1, 52.4] }, { lane: 5, name: "B. Swimmer", splits: [25.6, 52.9] }] } };
const timeline = raceTimeline({ pool });
console.log(timeline.frames.length, timeline.events.map((event) => event.kind).join());
console.log(drawFrame({ sport: "swimming", pool }, timeline, 30).includes("2 tracked objects"));
// 575 start,turn,turn,finish,finish
// true

raceTimeline(options, { fps, lead, tail, reaction, block, language }) takes ten frames a second, 1.5 s before the signal and 3 s after the last touch by default; a swimmer with no reaction time leaves the block after reaction (0.7 s). drawFrame, mountKyogijo(...).replay and <kyogijo-field> play it as they play any timeline. Pass { trailOf: ["home"] } for a wake behind each swimmer. The marks are circles with the lane's number on them, in a colour that reads on water.

Water polo#

The field of play is 25.00 by 20.00 m between the goal lines for men and women alike (Part Six Article 20.2.2). It lies in a pool 0.30 m longer at each end, where the nets hang (Part Six Articles 21.6.5 and 21.7.2.1). pool.table (bottom by default, or top) is the side of the official table.

A score puts the home team on the left: water polo lists the home team first, as soccer and handball do (score). The names stand on the decks at the ends.

Diving#

The well is seen from above with the boards' wall at the left and the dive towards the right. pool.platforms (5, 7.5 and 10 by default; 1, 3, 5, 7.5 and 10 are the rules'), pool.springboards (on) and pool.boards (the springboards of each height, 2 by default so that a synchronised pair stands side by side) say what stands there. Every distance is measured from the plummet, the vertical line through the middle of the front edge, as Appendix 2 of Part Four does.

The rules give clearances, not the size of the well; the drawing makes it 25 m across and 21 m deep, and wider if the boards asked for need more room. The springboards stand from the left wall (3 m boards outside, 1 m boards inside), the platforms from the right (the tallest the distance B from the wall).

Artistic swimming#

The routine area of the Olympic Games and the World Championships is at least 30.0 by 20.0 m and 3.00 m deep (Part Seven Article 12.2.2); elsewhere at least 15 by 25 m, of which 12 by 12 m is 3.0 m deep and the rest 2.0 m (Part Seven 12.1.1). pool.area: "olympic" (the default) and "minimum" (25 by 15 m, the deep part shaded and dashed). The floor is marked with lines in one direction along the pool, as the lane markings are (Part Seven 12.1.3); the judges' (Technical Officials') platform (at least 0.6 m high) is within 2 m of the edge (Part Seven 12.2.5); the starting platform (0.7 m) stands at centre stage (Part Seven 12.2.4 and 12.1.7). The platforms' sizes are ours, as the rules give their heights.

A natatorium#

pool.venue sets several pools in one hall, to scale, each drawn by its own sport's builder, with the deck drawn once, the paint of the water defined once and the names written under the pools. The pools stand at least 8 m apart (the rules' least distance between a swimming pool and a diving well, 10 m preferred and the default, Part Two Article 15.15.1). "natatorium" is a competition pool, a diving well and a warm-up pool side by side, with seating along the top; your own is { pools, apart, labels, seating }, each pool { sport, course, lanes, kind, name, x, y } (x and y, in metres from the corner of the hall's water, or none to let them fall: the pools stand in a line along the seating, top walls level, and a new row starts when a line would be longer than 125 m).

import { venueLayout } from "@johnmorrisdotca/kyogijo-stadiums";

const hall = venueLayout({ venue: "natatorium" })!;
console.log(hall.items.map((item) => `${item.plan.sport} at ${item.x}, ${item.y}`).join("; "));
console.log(hall.width, hall.height);
// swimming at 0, 0; diving at 60, 0; swimming at 91, 0
// 116 25.9

Two pools nearer than apart are an error that says the rule. The hall is a swimming drawing: its outline, layers and description are the whole hall's.

The Japanese words#

The Japanese text of the pools uses the words of the Japan Swimming Federation (日本水泳連盟) in its own rule books, read from swim.or.jp on 2026-10-13, and not a translation of World Aquatics' English. The main label is the rule's word; the everyday word that television and the newspapers use more is an alias, and is not written by the package.

The federation's books are, with the dates in their file names: 競泳競技規則 (2023-04-01), 飛込競技規則 (2026-04-01), 水球競技ハンドブック (2023-04-01), アーティスティックスイミング競技規則 (2026-04-23), プール公認規則 (2026-07-01) and 公認プール施設要領 (2025-04-01).

Scores, parts, zones and data#

A score is a dual meet's points, or a water polo match. range crops to a part: half and pool-end (the first 15 m) for swimming, half and goal-area for water polo, springboards and platforms for diving, half and centre-stage for artistic swimming (ranges). landmarks: true names the parts of each pool. Heat and zone layers have a zone set for each pool (layers): pool-lanes for swimming, water-polo-areas, and pool-thirds for diving and artistic swimming. The coordinate frames are the pools' swimming, waterpolo, diving and artisticswimming, in metres from the middle of the water (frames). The figures are SWIMMING, WATER_POLO, DIVING and ARTISTIC from /geometry, each in any unit by dimensionsOf.

import { dimensionsOf, surfaceSize } from "@johnmorrisdotca/kyogijo-stadiums/geometry";

console.log(surfaceSize("swimming", "ft"), dimensionsOf("swimming").laneLine.longLength);
console.log(dimensionsOf("diving", "ft").springboard.length.toFixed(2));
// { length: 164.04199475065616, width: 82.02099737532808, unit: 'ft' } 46
// 16.01

What is not here#

• The annexes' diagrams of the regulations (the pool diagrams, the diving field of play, the artistic swimming diagrams) are pictures. They were not read, so nothing is measured from one; the figures are the text's and the tables'.
• The backstroke ledge, the lane rope's wave-reducing parts, the lighting, the water's temperature and the turnover are in the rules and have no place in a plan.
• Open water, high diving, beach water polo and the dry-land facilities are not drawn.
• A tall drawing's names and times lie along the lanes instead of upright, because a lane is 2.5 m wide.

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