Blowholes are a fascinating phenomenon of nature along coastal areas where there is solid rock formation. The action of the waves against the rock over many years can create an underwater cave. In some instances, if there is a weak area above the cave, the force of the wave will push air through the crack or weak area of the rock until finally a hole opens. As the waves push a volume of water through the underwater cave, the air gushes up through that hole and with it a spout of water.
Depending upon tides and strength of the waves and the formation, the geyser-like explosion can be quite amazing. The blowhole at the East End of Cayman is not a huge one but it is fascinating on days when the conditions are good for a display of the power of the ocean.
There are lots of blowholes, many famous, around the world wherever there are rocky coastal areas with the open ocean pounding the shoreline. Several spectacular blowholes are located on some of the Hawaiian islands. There are others in Australia and Samoa as well as Mexico. They can be dangerous as unfortunately some have found. The Nakalele blowhole has been the site of several accidents with tourists getting too close and falling in. A few years ago a California man disappeared into the hole and is presumed dead.
Stand in awe and wonder. Just be sure to stand at a safe distance. Nature demands respect.