Vertical spouts & bubblers These are amongst the simplest types of fountain, but with a certain degree of visual flexibility. A vertical spout in a pond or pool projects water up into the air, to fall back into the same pool. The spout containing the nozzle or fountainhead is small and unobtrusive, so the visual appeal of these fountains comes from the water jets themselves. Bubblers are similar, but the nozzle/fountainhead is submerged under the water line. Different nozzles/fountainheads and varying water pressures can produce an array of different water jets, from fans with multiple streams, to high white-water jets (geyser heads) and billowing low white-water (foam heads). Changing the water pressure through these type of fountains will change their appearance, making them aesthetically flexible, and able to convey a range from tranquil and gentle vibes, through to energetic and dramatic ones.