← Range ArcadeWORLD Nº 013 · A RACE YOU CAN REWIND
⛵ paper boatsPICK A BOAT. SCRUB THE RIVER.

FIVE HEATS. FOUR BOATS. ONE RIVER THAT REMEMBERS.

Which boat
reaches the mouth first?

Bigger streams run faster, and every boat is somewhere along its route.
Pick one, then watch, rewind, and check the photo finish.

THE REGATTAHEAT 1 / 5
t = 0.000
⛵

A river built once.
Boats looked up forever.

Each boat shows its stream order and where it sits.
Choose the one you think lands first. Then scrub the race back and forth.
The finish is exact to the digit.

0 POINTS1 2 3 4 TO PICK · DRAG TO SCRUBPAPER BOATS

dropAt(droplet, t) is a binary search on cumulative travel time: t = 10⁹ costs one frame.

ANOTHER RIVER

Words grow another basin and another field of boats.

RACE NOTES

Speed comes from the stream's order.

The river is Lars Rocha's indexed drainage basin: tributaries join where the ruler sequence says, and a droplet's whole route to the mouth is stored as cumulative travel time.

Each heat shows four boats with their stream order and progress. Water moves at 0.55 + 0.16 × order, so a boat on a big stream is fast but may have far to go. Pick the boat you think arrives first.

Then Race, or drag the scrubber: any instant is a lookup, so rewinding is free. Ten points a right pick, five more for a photo finish closer than 0.05. Three stars is five for five.

THE REGATTA IS OVER

⛵

The river
remembered every race.

A LITTLE REGATTA FOR A FRIEND

Race me down this river.