I thought those relied on ground effect to achieve the required lift, which would prevent them from flying above the ground or water beyond the altitude at which ground effects exist?
Yes; parent was making a pun about it not taking off (in fact, the A-90 Ekranoplane could fly without the ground effect, albeit poorly). The substantive point though is that using the ground effect isn't as viable over rough seas such as those of the Atlantic as it is over calm, flat water due to the irregular astrodynamic shear forces among other reasons.
Doesn't matter what kind of water, significant interruption of air intake wrecks the engines. It's commonly what damages engines when they ingest birds, or in one case, a 737 taxiing got too close to side of the taxiway and ingested... snow. Engine blown.
Though it's worth noting that "significant water ingestion" is a design requirement of airplane turbine engines. You can see testing videos on youtube.
They are designed to fly through an amount of water (clouds) without damage or significant performance reduction.
I don’t think any of those ever really “took off,” so to speak.
I think they had a lot of trouble, with even slightly rough weather.
There’s a reason that every photo you see of them, has them zipping over a calm, smooth body of water, on a clear day.