You should... get up earlier to avoid onshore winds & crowds :-)
More seriously, I think you just lack speed. It is no use trying to turn if you do not gather speed first. It seems you are often too low on the wave, or in the flats in front of it. Learn and experiment to go fetch the wave power where it is, in its upper section.
You should "play lava floor", imagine that the flats in front are lava, and avoid them...
Hi Kevin
Try moving your feet a bit more too man. Get your feet moving forward and see if you can start trimming and unlock the waves power a bit easier (as per Colas' comments above).
It looks like your feet are planted on the tail and you're trying to do snaps but you don't have any power behind you and look too far back on a long-ish board as well as being caught behind the wave, in the flats.
It's hard to do snaps when you've essentially stalled - like you would to set up a barrel.
It's also hard to generate good speed in mushy waves - try to surf to what the waves are doing. Rather than try and blow em apart - just use the conditions to your advantage. If it's small, onshore and mushy - just surf accordingly.
The waves in your vid' are small,mushy closeouts - actually not that easy to surf (well) so you've gotta adapt to get the most out of 'em.
MD
Hire a foil, foils are the best at teaching you were the power of the wave is, you are trying too hard. Go and look at youtube clips of parko and curren, how they use the wave to gain power and then transfer their weight to the cutback. Also carroll is good at how to position yourself in the pocket.
You are riding a large longboard and need some waves with power. As dingo says you are riding mush that any surfer would find a cutback difficult on. Sup surfing is an evolution of surfing so study good surfers first. If you want an example of power, measure how far and fast you get pushed forward after taking off, if its like a metre then its slush and will lack the power to do a cutback. If its like 5 metres and fast then you can start to learn to bottom turn and trim across the face to gain speed.
Start on point breaks as they tend to be more forgiving than beach breaks. Sup surfing is not easy remember that.
Longboarding on a skateboard is also good practice at getting use to doing the more drawn out turns.
in mushy waves you have less room to move ,a shorter and more manoeuvrable board may help ...
but you looked ok 
on what you had and the conditions ,is your question ...how can i rip harder ?
As Tardy said, get a shorter and flatish board. Actually, your board has a lot of dead weight and useless surface at the front hyper lift nose. On a shorter board, you won't have to move your feet as said Dingo to do.
And a better choice of wave too ( hard to do in those mushy conditions as well as to stay higher in the wave, don't think to make the section just to stay in the curl to fetch the power instead of spreading it going down the wave.
You will do it soon, get closer every day ;-)
Such sloppy conditions and a long board . You are doing pretty well from what I can tell. If that was me I would be very satisfied . I reckon you would rip it apart on the waves with sub 8ft board which has inbuilt stability through its design
In waves like that it looked like you were doing ok.
On a short board you can throw it up. But not a long ride.
You made some sections. When conditions are crummy work on a few things, or even just one for practice.
For example, I am going to fade, plant my foot on the outside rail, and do a cutback on every wave on take off.
Practice what you think you need to work on the most in crap so you can style when the waves are decent.
I think you did well,a little over surfed probably due to board,however those conditions were not good,maybe look at a better board to surf.
Select to expand quotecbigsup said..
In waves like that it looked like you were doing ok.
On a short board you can throw it up. But not a long ride.
You made some sections. When conditions are crummy work on a few things, or even just one for practice.
For example, I am going to fade, plant my foot on the outside rail, and do a cutback on every wave on take off.
Practice what you think you need to work on the most in crap so you can style when the waves are decent.
What he says
