Every year, humpback whales travel to Tonga, to mate and give birth. During that time it is possible to swim with them. That day we saw a small fin break the surface, and swimming in circles, a sign that it was probably a calf coming up for air while it's mother was resting below. We got in the water and started swimming quietly. After swimming about 70 meters, we spotted shadows below us. So we waited, knowing that the calf would be back up for air soon. What we didn't expect is that when coming up, it would swim straigth at us and circling us! it was exhilarating, the calf kept coming towards us, swimming around and making eye contact. It was so inquisitive. I would have loved for the interaction to last forever, but after a few minutes, its curiosity seemed satisfied and it swam back to its mother.