Finally, the ship grounds itself near an inhabited tropical island and springs a leak. While Rollo dons a deep sea diving suit and submerges to patch the hole, the natives canoe out and take Betsy captive. When Rollo emerges from the ocean, the natives are scared off, enabling him to rescue Betsy and take her back to the ship. The natives return and try to board the ship. After a fierce struggle, Rollo and Betsy try to escape in a small dinghy. It starts to sink, and the natives swiftly overtake them in their canoes. Just when all seems lost, a navy submarine surfaces right underneath them and they are saved.