A particular river has certain size locks and bridges that drive the dimensions of a river cruise ship.  However, on occasion a change in water levels can cause those dimensions to go from tight to impassable.   When it comes to water levels, the first concern guests think of is low water; that the river is so low that there is not enough depth for the keel of the vessel – the “draft” for the ship to continue.   However the opposite of that is of equal concern; the water is so high that a ship cannot pass under a certain bridge.

Sometimes, this is known well in advance, but other times it is completely unexpected!  While water levels are unpredictable, it is important to remember that just because one section of a river is experiencing high or low water levels does not mean the entire river is affected.

Fun Fact:  The cruise line with the least draft is typically AmaWaterways.  Sometimes they are able to sail in low water when other lines cannot.

It is not an uncommon event, and though weather can be a factor, there is not really a time to avoid.   Weather factors could include a hot summer with very little rain, or a warm spring with rapidly melting snowcaps.  The main thing to know is that all of the river cruise lines have contingency plans in place, and they do their best to cause as little interruption to your vacation as possible.

The cruise lines have a few alternatives and the most common is to do a ship swap.  How does that work?  It is a very common practice at all times for a river cruise to be running a reverse itinerary cruise, typically on an identical ship.   On an uninterrupted cruise, you will pass sister ships on your same brand on a regular basis.  Of course, the size of the river cruise company makes a difference in this case.  The largest, Viking Cruises, has more than 50 identical ships on the rivers of Europe alone.  That is certainly an advantage!  

So let’s assume you are going Westbound on the Danube and there is unexpected high water between Vienna and Budapest, creating an impassable bridge due to the high water level.  Remember there is also an Eastbound ship that has the same problem.  So the ship will ask you to pack up your belongings and put your suitcases by the door.  You will then go on that day’s excursion as normal.  However, at the end of the excursion, you will take the cruise line’s motorcoach an hour or so (sometimes longer) to the Eastbound ship’s location.  The crew will have already cleaned both ships and swapped your belongings to the other ship, and in the same exact room.  Then the Westbound ship now becomes Eastbound, and your new ship (originally Eastbound) now picks up your Westbound itinerary and you continue on your merry way!  By the way this technique also comes in handy when a lock is broken or out of service.

Again, while Viking currently has the most riverships, there are many cruise lines that have multiple ships along the same itinerary, also going in opposite directions.  They too, can meet up and “swap” ships.

With extended sections of the river out of commission – which could be due to extremely low water levels for long distances – the cruise lines may take another approach.  Instead of a ship-swap, they will go as far as possible on the river as they can.  Depending on length from the original endpoint will choose one of the following continuations:

1.  have the guests stay aboard the stationary ship and use the cruise line motor coaches to take them to the unvisited cities for excursions and then back to the ship each day
2. Put the guests up in a central hotel (of similar quality as the cruise line), or hotels, and by motorcoach visit the rest of ports of call with the same cruise director and tour guides.

The last alternative available to them is to cancel the cruise, either during the cruise or well before your departure.  They use this as a last resort usually only when they feel they cannot deliver their brand experience to the guests.

In my experience, it’s best for the guest not to pre-emptively cancel the cruise for water levels.  First of all, by the time it becomes apparent, the guest will likely have already paid final payment, and there could be a hefty penalty to cancel.  And, if the cruise line chooses to operate the itinerary, it is not a covered reason to cancel with most travel insurance policies.

On the other hand, waiting for the cruise line company to cancel outright or offer options, can be a wiser route.   Most reputable companies in this case will allow a change of sailing date, or possibly a refund or credit.   If you do travel and experience issues, it is not uncommon for reputable cruise companies to give you some type of compensation.   

It is not in your control nor anyone else’s, and just like any other type of travel, there can and will be hiccups.  While we would all like our holidays to have ideal conditions we must accept that environmental factors are variables not in our control.

Fun Fact: When is the best time to river cruise for water level considerations?  There is never a time that you cannot be subject to high water or low water (or other conditions).   Early spring such in March & April could be more susceptible from ice melting too quickly from the mountains for high water, but then June, July & August could have long durations of high temperature causing low water.   Fall can be in danger (as it was in 2018) of very low water levels due to a season of drought.  While rivers are by their very nature unpredictable, when I choose the months to book my group river cruises it is usually in May, July, or September – which I consider equal.  

Low or high water is certainly not ideal, but it’s not the worst thing in the world either.   Be prepared in knowing that this could still be the situation upon arrival, and be ready for alternate methods of seeing the world unfold before you.   And then enjoy this vacation to the fullest – you are going to be in a beautiful part of the world. You will have a lovely time with the places you are going to see – they themselves are not affected by water levels!  
As you know the old saying: if you go into something looking for the negative, or go in looking for the positive, you will find what you are looking for.  So have a wonderful time exploring these historic cities!