[dragonwriter]

Those two sentences are contradictory. A swimming suit is not a boat, especially in "the most literal sense."

A suborbital manned spacecraft, OTOH, is a spaceship in every sense. (It's neither an orbital spaceship nor, say, an interplanetary spaceship, but it's definitely a spaceship.)

Saying they aren't is like saying a riverboat isn't a boat because it's not ocean-going.

[rbanffy]

A suborbital spaceship is analogous to a boat that can go into waters, just as long as they are knee-deep.

It can touch space, but a ship is not defined by its ability to touch the water.