Teresa certainly wouldn't drown in the seawater, but he still felt fear. The tactics of Ji Tianqi, or rather, the Security Administration Bureau, were somewhat unbeatable.
Firstly, his location had been locked on. Given his running and flying speed, it was impossible for him to escape Ji Tianqi's clutches.
Secondly, now that the Security Administration Bureau had made it clear that they were out to get him, the attitude of his 'subordinates' would probably all be the same as Buck's. Although he had reinforcements who were nearly as unafraid of the Security Administration Bureau as he was, like the Cloud Demon, he needed the opportunity and time to find them.
Thirdly, he had not sensed anyone around, and the Teleportation Gate was clearly activated remotely. This also meant the person who activated the Teleportation Gate was beyond the range of his superpower. This meant he couldn't fight back, he could only passively take the hits.
Furthermore...
And furthermore...