Other Advantages

Up close view to enhance the tsunami realism.
No exposure to tsunami waves, and a minimum exposure to an earthquake.
No or a minimum exposure to the harsh sea environment.
No need for dedicated human resources.
The warning would be individualized.
The tsunami warning would permeate through the public bottom up (vs. top down).
A city specific tsunami info. would be provided (localized warning system).
Ease of maintenance and the system exercise (Land based, easy access to the system).
Ease of upgrade (less expensive and hi-tech drone will be available in the near future).
Highly computerized (The system would predict accurate tsunami info.)
Utilize Hi-tech drones (Auto detection, avoidance, navigation, image recognition, etc.).
Existing communication system could be utilized.
Flexibility (It can be used not only for a tsunami disaster, but also for other usages).
Each city could built them in piecemeal from bottom up.