This altitude is already within the detection blind spot of the Anti-Air Warship.
Even the Early Warning Aircraft cannot detect targets at ultra-low altitudes very far, usually within about 300 kilometers, and interference from sea surface reflections shortens the identification and locking distance to within 200 kilometers. If the weather is too bad, it will be further shortened.
However, that's not the critical issue here.
Each F/A-18D is equipped with two mission pods, one carrying optical reconnaissance equipment and the other is an electronic warfare pod.
Inside this pod is a complete set of electronic reconnaissance and warfare equipment.
The crucial point is, this equipment can detect the electromagnetic waves from the air search radar carried on the Anti-Air Warships, as well as those from Early Warning Aircraft.
In fact, this is simply a radar warning device.
