Well, it might be dark in here, but Jamie's hearing was perfectly fine. Once he caught on that the Doctor was heading his way, he started to move toward the sounds, resulting in them catching up somewhere in the middle.

It was a bit of a relief, although that faint, slightly off-sounding buzz of the sonic screwdriver made it somewhat less of one. He had to wonder what happened to it to make it sound like that. Maybe it had something to do with whatever was wrong with the TARDIS...but he couldn't very well ask about it while trying to get out of a large body of water. And it did seem like it was helping point in the right direction, given the Doctor now seemed to know where to go. "Aye, all right."

He started to swim off towards the light, slow but steady. As long as it wasn't too far away, he figured he could likely make it without getting too tired. But, then there was that sensation again, the faintest tickle of something brushing up against his leg. It shouldn't be anything to worry about, he thought to himself. However, for some reason, he was beginning to feel nervous. "Hey, Doctor. You've not got any beasties living in this lake, have ye?"