Sometimes when you travel, Mother Nature throws a curveball. Usually you'll only need a raincoat, but more serious and dangerous weather can put a more permanent damper on your trip. With heavy rainfall and floodwaters rising across central Europe, river cruise companies continue to cancel and modify routes throughout Germany, Hungary, and the Czech Republic. So what should you do if your dream vacation is cancelled? Though river cruise companies have not adopted the Passenger Bill of Rights like many North American ocean cruise lines, you still have some options.

1. Go Anyway: While some cruise lines are able to switch ships and still sail, others have decided to anchor at shore. Even though the ships didn't leave the docks, many companies, including Viking River Cruises and Scenic Cruises, provided buses for passengers to continue on with their itinerary. "When there's high water, as there has been on the Rhone and Saone since the end of April, we use the ship as a base and operate as much of the sightseeing as possible by motor coach," a representative from Gate 1 Travel said. This alternative allows passengers to continue on with their travels while adhering to the original itinerary as closely as possible.

2. Rebook: If you were especially looking forward to sightseeing in multiple towns and along the river, talk to a cruise representative about rebooking your trip. Most companies don't want to lose your business and will work with to rebook at a later date. ADT announced they will honor the price of cancelled cruises if travelers book the same itinerary in 2014. Viking, who has also worked around the unexpected weather, contacted its passengers for its June 12 trip and gave them the option to take the bus-based tour provided by the cruise line or rebook their trip at a different time.

3. Get Your Money Back: Many companies provide refunds to passengers in the case of cancellations. Tauck, for example, does this. Avalon Waterways and Titan Travel cancelled tours this week and will provide passengers with full trip refunds and discount vouchers for their next trip. Avalon is giving refunds for the cruise itself and is also planning to refund any flights bought through them, or pay the change fees for passengers who bought air on their own.

For updates on current river cruise conditions, follow here.