Modern double hull tankers, with their fully "segregated ballast tanks" propose another problem.

Modern tankers also use segregated ballast tanks and these remove the problem of discharge of ballast water.

These so-called preMARPOL tankers were single hull only with some segregated ballast tanks.

To prevent pollution in case of grounding the ships were also built with double hulls and conformed to the IMCO regulations in respect of segregated ballast tanks even though they were regarded only recommendations back then.