To prohibit Russians seafarer to be hired by international companies at shipping industry.
To implement unprecedented actions by the UK Parliament and IMO in response to an unprecedented aggression by Russia.

The European Union has adopted three waves of heavy sanctions against Russia's financial system, its high-tech industries and its corrupt elite. This is the largest sanctions package in EU's history.
Oil Majors leaving business in Russia such as Shell and BP.
Russian seafarers are the source of income of foreign currencies (USD, Euro) into Russia's economy. This sector has to be sanctioned as well.

Sanctioned banking system of Russia will impose difficulties to shipping companies to deal with russian seafarers monthly wages transfer.  

Today Ukrainian sailors around the world are an absolutely integral pin in the wheel of world trade. Ships under the command of Ukrainian captains continue to sail safely and efficiently despite the harrowing conditions their families endure at home.