The opposite of the noun raft could be "submersible" which would keep you under the water rather than above. Or possibly "ballast" (weight to keep you underwater).
More arcane would be "pool" which is a water above a dry surface, while a raft is a dry place above a water surface.
*The less frequent use of raft to mean a large unspecified number (e.g. a raft of problems) could have the antonyms few or countable or numerable.
If I dived off the raft, the force of my dive would cause the raft to go the opposite way of my dive
The front of a raft is called the "bow." This is the part that typically faces forward when the raft is in motion, allowing it to cut through the water. The opposite end is known as the "stern."
They raft.
Types of raft foundation are 1. Solid slab raft 2. Beam and slab raft 3. Cellular rafts
The raft is breaking up, sir! Let's jump onto another raft as soon as we can. That's Tom Sawyer's raft.
The plural of "raft" is "rafts".
type / and type raft
raft concrete
The life raft began to sink.We should make a raft to get across the river.
George Raft is 5' 7".
Get Up on the Raft was created in 2008.
Raft spider was created in 1757.