Ballast introduced into a cargo tank on a chemical tanker which has been washed to such an extent that the ballast contains less than 1 ppm of the substance previously carried may be discharged into the sea without regard to the discharge rate, ship’s speed and discharge outlet location, but under certain conditions, which require:
Your answer is correct:
That the vessel is not less than 12 miles from the nearest land and is in water that is not less than 25 metres deep.