Another issue is the fuel tank, which would need to be much larger for any standard tugboat making long oceanic journeys. Support tugs however, are built for ocean travel and can handle offshore work.

However, the tugboat alone can't cross the ocean; it would never reach the iceberg, let alone New York. ... Start small, set a course and build iteratively in the right direction.

Another issue is the fuel tank, which would need to be much larger for any standard tugboat making long oceanic journeys. Support tugs however, are built for ocean travel and can handle offshore work.