Would these boots be good for sailing?
Yes. But that answer is tempered by the actual need for the boot. They will offer some grip and help avoid slipping, but only to a point. Being a neoprene boot they are not going to prevent slipping if you are going to need to brace your feet for leverage.
Gripper Round - BK16
3mm round toe boot
This covered split toe boot has a velcro arch strap and an elastic ankle strap
All seams are taped for added warmth
Superstretch neoprene on the upper ankle eliminating the need for a strap and assuring an easy entry and a snug fit
Ultra thin supergrip sole for a superb feel
Arch strap keeps foot secure