Objective

Ride the current down a sunlit lagoon and pass every drift net. Each net has one gap, and the gaps step further sideways than a straight line can follow.

The rope

A seahorse steers by gripping, and the only things to grip are the sea fans. Hold and its tail ropes the nearest fan ahead within 5.2 units. The rope settles to a fixed 2.8 units, so every swing is the same shape and leaves along the tangent at 44 degrees the instant you let go. A fan stands 4.0 units in front of every gap, so the line that threads it always exists. Rope a fan you are passing, not one you are pointed at: a rope pulled taut dead ahead swings you broadside.

Scoring

Five per net passed, two per fan rounded. The reef edge only stops you; the net is the one thing that ends a run.

The squeeze

Speed climbs from 4.2 to 6.4 units per second, the nets close from 10.5 to 8.0 apart and the gaps narrow from 4.6 to 3.6, all of it wound tight by 30 seconds. The rope never changes.