I used this type of snap hook on my anchors for 8 years and know several other people who use these. Nobody has had a failure. The hook latch is quick and reliable (no spring in the formal sense of the word -- it's held closed by the tensile strength of the bale itself). I have used two (one on each side of the boat) to connect U-bolt pad-eyes to my mooring lines for the last 10 years, and it has held through micro-bursts, thunder storms and nor'easters. Never a failure or even a hint of metal distortion, and I'm sure my boat has more windage than yours.

SWL is 4630 lbs. The breaking strength should be much higher but I don't know what the safety factor is. They come in differrent sizes -- You want the biggest most expensive one. See link.