Plesiosaur Lagoon Glide Lab (2D)

Lagoon Parameters

Pod size 5

More plesiosaurs share the same fish patches, so competition for the nearest one rises.

Turbidity 40%

Murkier water shrinks the visual detection radius each animal uses to spot a fish patch, forcing longer blind searching.

Current strength 35%

A stronger lagoon current drifts every animal sideways between flipper strokes, raising the corrective thrust — and energy cost — needed to hold a course.

Live Pod Stats

Avg cruise speed

0.0 m/s

Fish caught

Avg energy

100%

Detection radius

–

How it works — pulsed-thrust hydrodynamics

Each plesiosaur rows with two pairs of flippers in an alternating power stroke, which produces pulsed thrust rather than a steady push — modelled here as a sin²-shaped force pulse over each stroke cycle. That thrust fights a quadratic hydrodynamic drag (F = −c·v·|v|), the drag law that governs large bodies moving through water at high Reynolds number: double the speed and the resisting force quadruples, which is why cruise speed settles at the point where one stroke's average thrust exactly balances drag at that speed, not by intent.

Turbidity — shrinks the radius at which an animal can visually lock onto a fish patch; below that radius it swims a slow search pattern instead of a direct line, which lowers the whole pod's catch rate without changing its top speed.
Current strength — adds a time-varying lateral drift field across the lagoon; holding a straight course against it costs extra corrective thrust, which drains energy faster per fish caught.
Energy — burns with cumulative thrust output and regenerates only while actively feeding on a caught fish patch, so a pod that struggles to find food in turbid, fast-flowing water visibly runs its energy down.

Plesiosaur Fish patch Rock / obstacle