I'm not sure what other effects I should ignore, but the mass would increase. The ball gains relativistic mass as it accelerates towards the black hole.
PS: Assuming the boat isn't falling too (it's still in orbit), dropping the ball does nothing. You need to decelerate it (reduce it's orbital speed) for it to fall into the black hole.
PS: Assuming the boat isn't falling too (it's still in orbit), dropping the ball does nothing. You need to decelerate it (reduce it's orbital speed) for it to fall into the black hole.