Ah! The Caspian Sea Monster, an Ekranoplan, or ground effect vehicle. Used to be the largest and heavies aircraft ever built until the AN-225 was created. Basically, it uses the ground effect to “fly” at only a few meters above the water, at high speeds, essentially making it a jet-powered, and very fast hydrofoil, that just leaves the water entirely to reduce resistance.
Idea was to skim along at high speed, too low and fast to be detected, and fire nuclear missiles off its back.
