Rose said the camera was ruined, but the SD memory card was intact.
The final footage on the card, which Rose included in his video, shows a person with the GoPro strapped to their head looking at a woman in a wetsuit before jumping into the water and apparently losing the camera.
Rose said the camera continued to record for about a half hour underwater, allowing time for a crab to inspect the GoPro and take a short selfie video.
The footage was dated Aug. 13, 2015.
"Even though the camera looks beyond repair, I would love to give this guy his footage back," Rose wrote in text at the end of the video.