Answer: this is adaptation, but not in the way suggested in the question.
Step-by-step explanation:
The question is suggesting that the 1% or so of turtle hatchlings that make it to maturity are the result of a variation that gives a selective advantage. This is not so. The only thing being selected for is sheer luck. The underlying adaptation is that all eggs hatch within a short period, so that predators are overwhelmed by numbers and some offspring by chance make it to the water, still dangerous, but less so than the sand. After the hatchlings reach the sea chance will still be a factor, but it is at this stage that natural selection may operate on advantageous variations.
There are two reproductive strategies, common to plants as well as animals. Turtles represent one of those strategies, which is to invest resources to produce large numbers of immediately self-sufficient offspring so that at least some will survive. The other strategy is to produce one or few offspring and invest resources in protecting and feeding it or them until self-sufficient and capable of surviving to maturity.
These are adaptations which are selected for because they confer advantage for the species concerned. One or the other may be the better solution depending on the species. Mammals, for example, invest in the latter strategy.