We were looking for whale sharks when suddenly we saw a white shape floating underwater, a few meters under the surface. We could not tell what it was from the boat so we got in the water. I was amazed as I had never seen this animal nor a picture of it. We observed it for a while as it swam up and down the water. We could see through its body, it had a small shell and an oversized pig looking nose. When back on land I asked a few people online what could it be and found out that it was a glassy nautilus, quite a rare creature and there are very few sightings of it in the Indian Ocean.