To some extent, after such a long time of in-depth study on [Gravity Control], he can actually create a gravitational field around his body to keep the rain out.
But he didn't do that just now.
On one hand, his mental energy is indeed limited, as he is almost multitasking, having to constantly pay attention to any places on the ship that might require manpower, observe visible damages on the ship caused by the Saw-tooth Shark attacks, relieve the stress for the crew holding crossbows, and sometimes assist sailors in crisis moments when they're about to be swept off the ship by waves.
He simply didn't have the mental energy to maintain a Gravity Shield at the same time.
On the other hand, it was also a matter of interpersonal relationships.
Having just joined the team not long ago as a temporary crew member, facing a sudden crisis like this one together would help integrate himself.
