The aircraft
It increases.
If all other things are equal the speed will increase.However. As with most thing this question is based on false hidden assumptions.In reality, 'diving' is just a loss of altitude by pitching the nose downwards, and most planes actually SLOW DOWN when they 'dive' because they throttle back significantly at the same time as they are making an approach to an airport for landing.
If
The aircraft
When the throttle is opened wide, it accelerates down the runway.
The speed of the dives are not measured as part of the event.
it dives into a continental slope
it dives into a continental slope
No planes are faster than light.
from high speed dives into the ocean for fish
When the throttle is opened wide, it accelerates down the runway.
Get your speed to 75.