Glaciers move slowly, right? Well, once they do get moving, it's a sight to truly behold.

Tourists on a boat along Prince William Sound in Alaska saw firsthand how breathtaking a glacier can be when they got an up-close view of one collapsing into the water.

It starts out looking like a glacier waterfall and the boat's passengers cheer in awe before some grow worried when they notice a wave heading in their direction. Fortunately, someone on the boat's crew allays their fears by reminding them the wave will die out by the time it reaches their vessel.

It's truly a remarkable moment and serves as a potent reminder of the power of nature and the sometimes unforgiving climate of Alaska.