To find the rate of change, we divide the change in depth by the change in time.
The change in depth is 10 meters (since the diver saw something interesting about 10 meters lower).
The change in time is 10.1 seconds.
So, the rate of change in the diver's depth is $\frac{10\text{ m}}{10.1\text{ s}} \approx \boxed{0.99}$ meters per second.