"It's the only thing," said the Water Rat solemnly, as he leant forward for his stroke.

Her seat slides forward and back on tracks in the center of the cockpit, which increases the OARS 'Angle of attack as they enter the water — making each stroke longer and more efficient.

The dye revealed that much of the water pushed away is then sucked up again and sticks around as the jellies make their next stroke.