A collection of logs, boards, pieces of timber, or the like, fastened together, either for their own collective conveyance on the water, or to serve as a support in conveying other things; a float
a flat float (usually made of logs or planks) that can be used for transport or as a platform for swimmers make into a raft; "raft these logs" travel by raft in water; "Raft the Colorado River" transport on a raft; "raft wood down a river
(often followed by `of') a large number or amount or extent; "a batch of letters"; "a deal of trouble"; "a lot of money"; "he made a mint on the stock market"; "it must have cost plenty"
A speleothem consisting of a thin layer of crystalline material which forms and floats on the surface of a cave pool Sinks if water surface is disturbed May form many layers in a dried out pool Cave - Depositional Features Ref HF
A raft of people or things is a lot of them. He has surrounded himself with a raft of advisers who are very radical = host of. A great number, amount, or collection: "As the prairie dog goes, conservation biologists say, so may go a raft of other creatures" (William K. Stevens)