Yeah but what if they attacked? What if there were subs present and they submerged.
And the other possibility I was thinking of, let say that Ger has a fleet next to Uk in SZ7. Uk has two fighters four spaces away from SZ7. Can those fighters attack when a CV has been purchased knowing they’d land there if they survived?
The fighters could legally attack, since the placement of the carrier would allow them a landing spot. However, since they used all of their movement to get to the battle, they would have none left to retreat, so it would be a fight to the death. The fighters would either clear the sea zone (including possible submerging by subs) or be destroyed. If the fighters survive, the carrier must be placed in the sea zone. If they don’t the carrier could still be placed in the sea zone, or it could be placed in another sea zone if there is another one available.
Edit: Just to be clear, this answer applies only to LHTR, as using all of a fighter’s movement for combat movement would be legal under the box rules only if an existing carrier moved into the sea zone during either Combat or Noncombat Movement.