Board Thread:Questions and Answers/@comment-87.8.24.239-20170806095559/@comment-454133-20170806161538

Whether or not it's a ship's ability or some other game effect, this sort of measuring is allowed and necessary. In this case, target locking is in fact an ability that's placed on the ship by having the lock icon (or being granted a target block by some effect, so it's still the ship performing the ability), so it should count as a ship ability. If it didn't count as a ship ability then it would still have rules somewhere granting the chance to measure. You can't acquire the target lock if you're just barely outside of range 3 (or within range 2 if you have Long Range Scanners), so measuring has to be part of the ability.

Pro players frequently make use of this, BTW, deliberately attempting to target lock a ship that is clearly out of range just to get a chance to hover the ruler over the playing field and gauge distances. It gets less legit if you swing the ruler around to measure another ship that's not in line or close to being in line, but otherwise it's fine to assess additional information while measuring range to the ship you're trying to lock.

Worth noting, other abilities that can trigger measuring are common. Any time the ability triggers or a rule references range for a specific event, you or your opponent get to measure at that time (but not before). For example, when you trigger Airen Cracken after performing an attack (grant an ally an action in range 1), you get to measure to find an ally in range. But you can't measure before that event, e.g. when that ally is attacking or during the activation phase because you want to know whether to spend your focus, or barrel roll etc -- you have to guess how close you are without measuring, because nothing is granting you the chance to measure at that moment.