Steps to Reproduce:

Step 1- Create a predicate which includes "can_see_sky" condition. It would look like that:

^{{
    "condition": "minecraft:location_check",
    "offsetX": 0,
    "offsetY": 0,
    "offsetZ": 0,
    "predicate": {
      "can_see_sky": true
    }
  }}

Step 2- Ride a boat and use this command when there are no blocks above you:

^{/execute if predicate minecraft:exposed_to_sky}

Observed Results:

The command failed.

Expected Results:

The command should have passed.