To answer your question, yes I used a GoPro Hero 4 Silver for all the shots, including on-land. Now, the new GoPro Hero 5 has a few great features that I wish I had: video stabilizaIization, wind noise reduction and voice control - all very useful for what we do on the water. The Hero 4 Silver delivers nice usable clips at 1080p (HD) resolution @ 60 fps. It can go 4K but the frame rate is then much lower and slow-mo during editing is no longer an option!
I use aluminum floating selfy stick for on-land and underwater shots so it's easy to hold on to. I also use a Flymount for all the on-the-sail shots. See here: flymount.com/flymount-original/ This mount is a bit expensive but it is very versatile and will attach very securely anywhere on the mast and boom. There are less expensive options I haven't tried (quick clamp, like what you would find in a hardware store). The clamp is probably easier to move around on the fly but is probably less secure.
I also used a Garth helmet with a GoPro mount. The mount comes with a stainless steel hardware (screw and blind nut) that effectively secure the mount to the helmet so you don't only rely on the adhesive of the mount to keep the camera from flying in the water! I haven't yet lost the camera while sailing but according to users online, the weak point seems to be the housing mounting plastic tabs that can break pretty easily. The issue is that the housing has no feature where you can attach a leach to prevent the camera from taking a trip in the water if the tabs break-off. If you see it happen and the camera has a floaty, great! If it break and falls off and you don't notice it right away, good luck to find it even if it's floating on the surface!
I haven't tried other action cameras out there. I bet there are some good ones, but the GoPro Hero 5 can shoot super HighDef at high frame rates and seems to excel pretty much in all features and benefits. I'm very tempted to get one of these and sell my Hero 4 Silver...
Looking forward to watch your upcoming Vids, Chris! Cheers
That's a great vid, Greg, and great choice of music, too! Greg, wondering if you can say a little about the camera you used to film this. I'm assuming it was a GoPro? If so, did you shoot all the shots with it (including the on-land ones)? What model are you using, and how does it compare to other models in the same line? I'm in the market for a water-proof camera. Thanks.