The specific tolerance within that 8-13ft range is driven by wave period. Long period waves lets us operate more towards that 13ft end because you can contour the waves.
I believe that max demonstrated wave height will have more to do with the height of the hydrofoil than the wingspan / ground effect distance.
Having said that, I'm pretty sure the much larger Monarch (their further future 50-100pax model) will probably have longer vertical supports on the foils.
Sure, that makes sense. The large swells in that region tend to be long period. Contouring the swells up and down is going to make some passengers motion sick, but probably not as bad as a regular ferry in the same conditions.
Ah I see the confusion - that overflight wave tolerance is defined by an emergency landing condition. In the extremely low probability chance that the seaglider needs to perform an emergency landing, the passengers need to be safe. That defines the 8-13ft window.
In no cases are we contouring waves in flight. We fly straight and level. Typical flight altitudes are 10-30ft above the wave peaks. The waves are well below us.
Having recently spent time watching many whales breaching well into your airspace, I wonder if you have any thoughts on avoiding right-of-way disputes with charismatic megafauna?