To enter the United States of America, you need a visa issued under the right category, which depends on the reason for your visit. Depending on the reason for your visit, there are many immigrant and non immigrant categories under which you can apply. These categories include D visa too.
It is a non-immigrant visa that is issued to foreign nationals working as crew members on board sea vessels. Foreigners working in the international airlines in the United States can also apply under this category if they are providing their services for a normal operation. However, these applicants should have the intention to depart the country on the same or any other vessel within 29 days.
Foreign nationals can apply under this category if they work on a commercial air plane as a pilot or flight attendant. A captain, engineer, or deckhand working on a sea vessel can also apply under this category. Other professional foreigners who usually get this visa are lifeguards, cooks, waiters, beauticians etc., on a cruise ship as well as trainees on board a training vessel.
However, not all foreigners on a vessel require this visa. For example, foreign nationals working on a private yacht cruising in American waters (for more than 29 days) cannot apply for D visa. There is a different visa category for them. It is essential that you apply under the right classification.
But, what if you need to enter the United States first to join a vessel? In these situations, you need a combination of C-1 & D visas. The former category is for those foreign nationals who want to travel to the country in immediate and continuous transit and then to other country.
The many categories and subcategories of US visas can cause confusion among applicants. To avoid mistakes in your application, you should get in touch with a professional immigration lawyer in the US city you will be visiting or arriving at. For example, if you are going to arrive in Florida, then you should consult with the best immigration lawyers in Florida as it will be easier for you to get immediate help (if needed) when you arrive. The immigration lawyers can assist you in the application process ensuring the visa approval.