Cruise Ships and the Ocean Coexisting?

This week I found information on a couple that not to long ago was on a trip in Puerto Vallarta. They decided to go explore some underwater caves, unfortunately their snorkelling trip was cut short due to a passing by cruise ship. The couple reported that as the ship passed by their was a bubbling green algae substance coming out the back. Their was a smell that was so bad due to the ship dumbing its its tanks they had to get out of the water. 

If this continues to happen how can the ocean be protected from the hazards that come along with cruise ships? It ends up being quite ironic because cruise ships rely heavily on the coral reefs, marine life, and clear blue water to attract their customers. Yet they have no problem polluting and ruining that environment. 

Due to being caught dumping illegally some cruise ships are required to have environmental officers. However like most things companies are finding away around this too. It has been reported that these officers are getting paid a lot and may not be so inclined to call out their employers when the correct producers aren't being followed. 

After everything is said and done I really believe that they only way cruise ships and the ocean can coexist is if cruise ship companies really want to protect they environment. People will always find away around things that they do not want to do. Until there is really awareness around this huge ongoing problem, we may continue to hurt the environment to the point of no return and not even be aware of it.