What this means is that provided there is no extraordinary circumstance, Catholics are bound to attend Mass wherever they are located in the world. If a Catholic goes on vacation, it is his/her obligation to find the nearest Catholic church to attend on Sunday.
This isn’t always easy to do, though technology and the internet have greatly helped in this regard.
One of the most reliable places online to find a Catholic church is MassTimes.org. You are able to enter in any address in the world and find the nearest church. Included in the results is the ability to search by a specific Mass time if you have a limited window when you can attend Mass. They also have an app for mobile devices that is extremely helpful.