Just concluded a trip in nuevo vallarta. There is very little info on conditions so I thought I would post so people doing future searches have a little to go on.
All the info I could find said kite surfing was in bucerias. I couldnt figure out if this was a legal issue or just that is where the schools were because the beach is public. Turns out I could kite on the private beaches. Two years ago we stayed at the marivales (I think) and conditions were similar, but the water quality was a lot better further away from the river. Was also able to launch from their beach.
We stayed at the grand luxxe vidanta which has a huge private beach. I was able to launch there with no problem. You need to be able to self launch, but the beach is relatively empty. I used the rope for the swimming area buoys to attach a launch tether, but there was plenty of room to launch without a tether.
I did have to go to the kitezone store in bucerias to buy a 12m kite and get a pump tube. It was $9 US each way. They are reasonably well stocked and have ozone kites. They do teach foiling so have access to foils, but dont think they rent them out. My 12m had a leak so I ended up buying a used kite school ozone catalyst from them for $950 (including bars). It was still somewhat crispy and had no repairs. Definitely a desperation purchase.
The wind was light running about 10-15, but it was just strong enough for a 12m kite and a 138cm board (I weigh 175). The biggest issue was when the wind was straight onshore, the swimming areas dont give much room for tacking. Plus the parasailers are constantly launching and landing and I didnt want tangle lines. The surf was small but the wind direction and light wind made it so I couldnt kite through the surf. I had to walk out past the surf and then body drag a little further out to get far enough out to pass the swim buoys.
I use the flamingos AMK ikite wind meter which seemed pretty accurate.
The dates were july 1-july 4 2018 if you want to look up the wind history.