I may have tried to hide out near the false canal where Zaroff lured ships in to break up on the rocks. There may have been a chance to find a skiff from one of the boats or even signal a ship before it broke up and sunk.
Chances of this plan working do seem slim though.
I think I would have realized it was hopeless to try to elude Zaroff on his own island, and I have no knowledge about building traps or other such defensive devices. I would probably have taken a chance on swimming out to sea and trying to go around behind the General as Rainsford finally did. If I could find a boat, as suggested in post #4, that would be great. (It occurs to me that Whitney might have turned back when he discovered that Rainsford was missing from the yacht. And if Rainsford had a boat, he might have a hope of reaching the yacht. But that is another story.)
In accord with the previous post, there are few men who could have defeated one so skillful and clever as General Zaroff, who also has so many sources that he can use. Perhaps, one in the position of Rainsford, having heard of the sinister Ship-Trap Island, would not have been as bold as Rainsford to knock on the chateau door after sighting it.
This action of Rainsford has always raised a credibility question for me as a reader. Why did he not hide for the night near the shore and hope that his ship would look for him the following day? Or remain hidden and watch in the daylight for what activity is on this island? Of course, then, there would be no story such as it is with a character of the confidence and bravado of Rainsford.
I'm not sure that I would have had the survival skills (and definitely not the knowledge of booby-traps) that Rainsford possessed. Rainsford used his skills appropriately, and they kept him alive at the end. I used to throw a knife pretty well as a youngster, but even if I had been able to use the knife, there were two men and many dogs with which to deal. I am a good swimmer so, like Rainsford, I would have probably headed for the coast and attempted to swim for it rather than face Zaroff and his pack. However, Rainsford may have been the only man on earth capable of eluding Zaroff--both world-class hunters who rarely missed their prey.