They've been absolutely solid in over a month now of wearing the watch 24/7 for everything from sports to DIY to gardening and everyday wear. The silicone material, to me, seems like it will be less prone to fatigue cracking over time than my Fenix 3 strap too (and I happily wore my Fenix 3 over the top of a wetsuit whilst surfing last summer). Clearly there's always going to be some weird circumstance where any strap might become undone/break whilst swimming in among loads of other folk in a Tri race, but I can't see these quickfit bands being any more prone to issues than another type of band (less perhaps the NATO bands that weave over the bars and under the watch - you'd probably find that shark would eat your arm before one of those let go ;) ). Perhaps worth asking Ray Maker for his thoughts in the comments section of his Fenix 5 review; he's probably got the best breadth of experience of different watches and straps worn during tri swimming.
I accidentally slide the release lock, thus removing the band when I wash the watch under tap water. Happen twice.
Well, the straps are designed to come off when you have the watch off you arm, like I'm guessing you did, try sliding that clasp open with the watch on your arm.
You want security, use the Nato strap. This thing is awesome for these type of events. When you are taking account what you paid for the watch, I would hate to loose it in the ocean, I would definitely not chance it with the stock strap. Don't get me wrong, the stock straps are pretty durable but not like the Nato straps that are secured by the extra band that goes underneath . They are easily washable as well and very comfortable.
You want security, use the Nato strap. This thing is awesome for these type of events. When you are taking account what you paid for the watch, I would hate to loose it in the ocean, I would definitely not chance it with the stock strap. Don't get me wrong, the stock straps are pretty durable but not like the Nato straps that are secured by the extra band that goes underneath .
They are easily washable as well and very comfortable.
I honestly wouldn't worry about the quick fit bands disconnecting. They are very secure.
That said, it would always be prudent to inspect the band for cracking, and inspect the quick fit clip to make sure the spring isn't stuck. I think it would be fairly obvious if you were in danger of having the watch "fall" off.
There's virtually no chance of the quick fit mechanism failing. I just tried to take the band off with the watch on my wrist and I couldn't slide the mechanism.
Off your wrist it's quite easy to detach but on your wrist you have no chance.
There's no way it could come off while swimming unless you had a catastrophic failure of the watch band which would be something that could happen to any band.
I've been impressed by the overall quality of the watch band. Even though it's thinner than the F3 standard rubber bands the silicone is of a sturdier quality compared to the Garmin F3 silicone bands and yet the F5 strap is still more comfortable than the F3 standard rubber watch band.
I agree with JoseBequer that if you really want to 100% secure then use a NATO band. It will of course cover up the optical sensor but that won't work in the water anyway, and if you're doing a triathlon or other such sport you should be using a tri/swim chest strap for heart rate.
I was in a sail boat race, sitting on the high side with my watch secured tightly to my left wrist. Next thing I feel is a snap at my inner wrist opposite the watch face. I look down and see the watch hit the water, quick fit bands intact on both sides of the watch. The silicone band failed.
I bought this watch in April 2018, free dove, scuba dove, backpacked....and by July it was at the bottom of the Pacific after a band failure .
I am STILL saving for it's replacement. Garmin did offer to help me out with this, but the replacement is nearly as much as my first purchase.
