Preheat the oven to 250°F. Line a large rimmed baking sheet with parchment paper.
In a medium mixing bowl, combine the granulated sugar, cinnamon, and sea salt. Set aside.
In a large mixing bowl, beat the egg white, water, and vanilla extract until frothy, approximately two to three minutes.
Add the pecan halves to the egg white mixture. Stir until all the pecans are evenly coated.
Sprinkle the cinnamon sugar mixture over the pecans and gently stir until completely covered.
Spread the coated pecans in a single layer on the prepared baking sheet.
Bake for approximately 60 minutes, stirring every 15 minutes, until the coating looks dry and the pecans smell toasted.
Remove from the oven and allow the pecans to cool completely on the baking sheet for approximately 30 minutes.
Gently separate any pecans that have stuck together. Serve or transfer to an airtight container.