Don. In your paragraph: " during a Dive, you state " If the main group exhaustvalve grindingprocess did not form a perfect seal...... you may say: in the rare event of not having a successful grinding of the group exhaustvalve causing a major waterintusion exceeding the draining capacity of the inboard main exhaustvalve and the engine exhaust manifold to be flooded, water might enter the main engine via the exhaustvalves in the cylinderheads.....
You may of course use your native language to the express the meaning, but avoid leaving an impression that this was a normal event. Although an unsuccessful grinding was quite common it was very seldom so bad that it resulted flooding the main engine, the internal drainage could usually handle the leakage.
On the same page you state : after a dive you should never start the engine by air.... Normally you always start by air, but before starting after a dive with waterintrusion you should turn the engine manually with open indicatorcocks before a normal starting, which means blowing starting air through the cylinders with open indicator cocks prior to shutting the cocks and run the engine by air before startingfuel is added. Turning the engine by hand for checking/draining the cylinders can be done immediately after a dive which is often done if water intrusion is observed. It might be a bit complicated, but in many cases you want to be ready for exhaust blowing as soon as you surface and then you are usually preparing the engines for start before surfacing. As you are aware of the CO does not like to increase the internal over pressure so you are careful with using too much air in the starting preparation otherwise the CO might be ejected through the tower hatch when he enters the bridge.