Joining a merchant navy ship

Ship's crew members are not eligible for 72 or 144-hour transit. You will have to apply for appropriate visa in advance at Chinese embassy in Zagreb.

It doesn't. You need a crew visa unless holding a visa-exempt passport.

Unfortunately, if you are a Croatian citizen, your passport is not visa-exempt.

Dear Sir, thanks for you reply. The problem is if a crew member gets ill and needs to be relieved urgently, the the new crew member need more than 14days to obtain visa at chinese embassy and by that time the ship is gone or even delayed in sailing without key persons. What to do?

I perfectly understand the argument and I'm more than certain that the Chinese embassy will understand the circumstances and will issue a crew visa noticeably faster than 14 day. You should act as soon as possible. Unfortunately, you will have to wait until Monday.

Thanks for replying.
Cargo ships must have crew but can have passengers too.
Is the 144hr transit applicable if i am flying into China and joining a cargo ship as a passenger?

No, this is not possible for simple reason. Shanghai, Beijing (in reality Tianjin), Xiamen, Qingdao have designated ports of entry that are eligible for 144 hours free transit. All of them are cruise terminals, i.e. dedicated to passenger ships. There is no option that you board cargo ship through any of the mentioned passenger terminals because the crew members and also the passengers on cargo ships that dock in cargo harbors have their own, separated ports of entry when they exit/enter China.

No. That's only applicable for those on cruise ships.

Dear Zupan, thank and sorry for being persistive as this is a big problem to me. I do not fully understand your reply. Once i land on Pudong, i need to show the ticket for being passenger on a cargo ship at the airport immigration office and they decide whether they will let me in or not. Afterward the agent takes me to the port immigration office to allow boarding of the ship. At which point above i would face problems? Thanks

You will face a problem when trying to board your flight to Shanghai. The airline will deny boarding because you do not have an onward ticket on a cruise. Passenger on a cargo ship won't be acceptable to the airline.

As already mentioned by Fred, you are not eligible for any kind of visa free transit in China, unfortunately. The reason is simple, in order to be allowed to board the ship in China and enjoy visa free transit, you have to board on passenger (cruise) ship and not on cargo ship. Passenger ships have their own, separate immigrations facilities, while cargo ships have totally different immigration facilities where the staff does not have authority to handle visa free passengers. Indeed, if you try to perform the check-in, you will be refused and your money will be wasted. You should, as I have previously told you, obtain your visa at Chinese embassy in Zagreb. Simply speaking, there is no other way.

Dear Zupan, thanks for clearing things out. Its great to have somebody who can thoroughly explain things out.
Best regards