To determine the rate of change in the diver's depth, we need to calculate the change in depth and divide it by the time taken to make that change.
The diver starts at a depth of 15 meters below the surface and descends to a depth of 25 meters below the surface (15 m + 10 m = 25 m).
The change in depth is:
\[ \text{Change in depth} = \text{Final depth} - \text{Initial depth} = 25 , \text{m} - 15 , \text{m} = 10 , \text{m} \]
Now, we can calculate the rate of change in depth per second:
\[ \text{Rate of change} = \frac{\text{Change in depth}}{\text{Time}} = \frac{10 , \text{m}}{10.1 , \text{s}} \approx 0.9901 , \text{m/s} \]
Rounding to the nearest hundredth, the rate of change in the diver’s depth is:
\[ \boxed{0.99 , \text{m/s}} \]