Welcome to the club mate
You can try this
If you use a low Ar kite it's much easier to relaunch, just pull on
the bottom line, the kite will roll over and ride to the edge of the
window, pull on the top line to launch. As you're using average to
high AR kites you will have to get them on their back to relaunch.
The best way to get good at this is to practice in
the shallows. Its a hell of a lot easier to relaunch a high AR kite
in the shallows than in deep water, especially in light wind (below
10 knots). Below 7 knots anyone will have a hard time in deep water.
It is easier to get the kite back up in light wind if you put
your board on. Instead of dragging down wind youÃ¢â‚¬â„¢ll hold your ground much better and put tension in the lines
and the kite will launch better.
You can practice this even on a light wind day by drift launching,
just walk into the water with the bar and kite, leave your board on
the beach. Drop the kite and let it drift down wind. When the lines
are taught, jerk on the bar (pulling in about 2 m, 4/5 armÃ¢â‚¬â„¢s lengths, of centre line then
letting go is ok too) then run towards the kite, if the water is
pretty shallow a few steps will have the kite on its back, you'll be
amazed how easy it is. Once it gets on its back you have to pull on
the top and bottom lines alternately to get the kite in the right C
shape, this is just something you'll learn by doing it, basically you
have to balance the kite so it don't fall over while you pull it into
the C shape, again in shallow water is 100 times easier and less
time/energy consuming. When you have the C shape keep pulling the
bottom lines until the kite reaches the edge of the window then pull
the top lines to launch, in low wind don't launch it too vertically
or it will stall and fall and you're back to square one. Once you
can do it in the shallows try in deeper water but remember you'll
need more wind.
If the wind is strong pulling in the middle leader can be energy and time consuming and the wind can blow the kite downwind so fast swimming doesnÃ¢â‚¬â„¢t work, so itÃ¢â‚¬â„¢s better to pull in about 2m (4/5 armÃ¢â‚¬â„¢s lengths) of one of the brake/side leaders while swimming/walking to the side, in stong wind the kite should roll over straight away and start launching, but anyway practicing in the shallows will give you more feeling.
If all else fails you can try letting it go to the leash because the kite should flap out on its back, then when you recover the bar balance the kite as above to get it into the C shape then pul the bottom line to get it to the edge of the window and then the top line to launch, using the bar obviously to pull the lines.
There will still be times you won't be able to relaunch in light
wind, no one can it's just part of the game.