First of all, birds can't really swim. Most birds seem to prefer their bathwater coming down vertically in a shower, or in a shallow dish.
I have been reading up on freeflight and it's pretty intriguing. I haven't taken a course yet, but I plan to in a few years to better understand the parrot psychology -- though I probably wouldn't ever put the flight skills to use outside....
The first video seems as though the macaws are used to flying in wind and they appear confident. However, I saw seabirds out over the water. Seagulls are bullies but it could have been another species of bird. Part of freeflying safely is not taking your birds out when you can see other birds that could be potential predators. A couple of times, the macaws skimmed down pretty low over the water, and sharks have been known to jump up and grab seabirds.
The second video with the lovebird had me biting my nails. Lovebirds (and other small parrots like cockatiels/parrotlets/etc.) are hawk bait. Free flight is much safer with something larger like an amazon, one of the large cockatoos, or a large macaw.