"Squirt boaters are underwater glider pilots.
Instead of soaring on thermals, they fly in whirlpools."
THE DISCIPLINE OF SQUIRT BOATING
Squirt boating is a esoteric discipline of whitewater kayaking that originated on the rivers of West Virginia.
The sport involves paddling extremely low-volume whitewater kayaks called "squirt boats".
The current evolution of squirt boating involves "flying" these wing-shaped kayaks underwater into whirlpool currents.
Flying underwater is called a "Mystery Move."
Harry in a typical squirt boat
SQUIRT BOAT DESIGN
Squirt boats are custom-made fiberglass kayaks that are shaped as underwater wings.
The latest generation of squirt boats were actually designed in a one-of-a-kind "water tunnel" testing facility in West Virginia.
The boat's contours were designed to maximize laminar flow and minimize turbulence and stall.
Squirt boats have extremely low volume with minimal buoyancy so that they sink with minimal effort.
Top and side views of the squirt boat airfoil
The cross section is that of an upside-down wing
Notice the foot bumps that allow for some comfort
The typical wing of an aircraft is based on the Bernoulli Principle.
Laminar flow over the wing creates lift:
A typical airplane wing.
The cross-section of a squirt boat is an upside-down wing that exerts downward forces instead of an upward lifting force.
Squirt boats are multi-layer fiberglass and resin boats that are hand laid on a mold.
This allows for custom designs on the boat in brilliant metal flake and pigments.
Then the two halves of the boats (top and bottom) are sawn down individually to fit the owner as tightly as possible before being fitted together.
This "chop" minimizes the boat's volume.
A squirt boat has to be as small as possible to sink effectively.
"If it don't hurt, then it don't squirt."
Squirt boaters will usually forgo the use of a life preserver because of the obvious added buoyancy.
THE MYSTERY MOVE
The Mystery Move is simply a flight underwater.
The squirt boater will dive into a downward-flowing current such as a pourover on the corner of a rock, or a whirlpool.
He engages the edge of the boat as a wing in the current and literally flies down underwater.
Spinning the boat increases stability of the wing (think of a spinning top), but also creates flow over the wing.
A skilled squirt boater can travel up and down between layers, or even travel from one spot to another.
The length of the ride is limited by a combination of breath-holding capability, fear and external currents.
Typical Mystery Moves are 5 to 15 seconds in length, but the record is approximately 35 seconds.
Here is a video that demonstrates typical Mystery Move:
