Apart from Selfrescue..
The main lesson to be learned here is 'Study the Wind shifts & fluctuations' !!!
Just because you have a 12
Blow kite, it doesnt mean you can kite in 5 knots. Did you not see the shiny spots on the water start to increasingly appear as the wind lines started to dissapear

Noob error - you were lucky to have someone to help you... this time. Dont let Stupidity get you next time !
When the wind starts dropping & everyone knows when that happensGet out of the waterWhen the more experienced guys start heading in, thats usually a pretty good indication (less or more wind)
P.s Noob

put ya name on your board too