raft (n.1) Look up raft at Dictionary.com
"floating platform," late 15c., originally "rafter" (early 15c.), from Old Norse raptr "log" (Old Norse -pt- pronounced as -ft-), related to Middle Low German rafter, rachter "rafter" (see rafter).
raft (n.2) Look up raft at Dictionary.com
"large collection," 1830, variant of raff "heap, large amount," from Middle English raf (cf. raffish, riffraff); form and sense associated with raft (n.1).