It may come as a surprise, but the canals in Venice aren’t very deep – less than 10 to 15 feet, and even that can vary with the tides. This is why you won’t see large boats filled with people, only the gondolas with much smaller capacity. Out of the more than 150 canals in Venice, some are shallow enough that they have frozen in cold weather and some have even “gone dry” from time to time due to weather patterns and tides.