Spinner dolphins live in groups called pods, which can have anywhere from a few dozen to several hundred individuals. They love to ride the bow waves of boats, shooting ahead through the water just in front of the hull. Watching a pod of spinners race alongside a ferry, leaping and twirling, is one of the great ocean spectacles of Timor-Leste.
Scientists are not completely sure why spinner dolphins spin. One idea is that the spinning helps them shake off small fish that sometimes cling to their skin. Another idea is that spinning is a form of communication - the loud splash when they land might signal to other dolphins in the pod. A third idea is that they simply enjoy it. Given how often they do it, enjoyment seems very possible.
Spinner dolphins are smaller than the bottlenose dolphins most people picture - they are about 2 metres long, with a long, slender snout and a distinctively striped pattern of grey, white and sometimes pink on their belly. They are fast swimmers who can reach speeds of 25 kilometres per hour.
In the deep waters off Timor-Leste, spinner dolphins often feed at night on fish and squid that come up from the deep ocean. By day they rest and socialise near the surface, making them easier to spot from a boat. Whale-watching trips from Dili regularly encounter both spinner dolphins and sperm whales in the same stretch of water.