I have launched from a boat without a reel bar. Basically, you set up you
kite on the boat and ask a person to hold onto the kite. You attach your
lines to the kite and then hop in the water upwind from the boat. Unwind the
line on your control bar as the wind pushes the kite downwind. My kite is a
Naish, so it has to be launched on the edge of the wind window. I asked my
wife to drive the boat to the optimal location and then asked the person in
the boat to let go of the kite. The particular day I was out was a light
wind day, so water relaunching was difficult with my Naish 9.0 kite. I asked
the people in the boat to pick up the kite and get it in the proper position.
It made relaunching a breeze.
A reel bar would help when you get in the water. It would prevent the lines
from getting tangled, especially if you were in high wind conditions.
Of course, the best part about using a boat is that you don't have to walk
after being blown downwind. You can also launch away from rocky shores and
other obstacles that line many beaches.
Give it a try!