Highly hydrophilic cotton fabrics were rendered superhydrophobic via electrostatic layer-by-layer assembly of polyelectrolyte/silica nanoparticle multilayers on cotton fibers, followed with a fluoroalkylsilane treatment. The surface morphology of the silica nanoparticle-coated fibers, which results in the variety of the hydrophobicity, can be tailored by controlling the multilayer number. Although with the static contact angle larger than 150 degrees, in the case of 1 or 3 multilayers, the fabrics showed sticky property with a high contact angle hysteresis (>45 degrees). For the cotton fabrics assembled with 5 multilayers or more, slippery superhydrophobicity with a contact angle hysteresis lower than 10 degrees was achieved. The buoyancy of the superhydrophobic fabric was examined by using a miniature boat made with the fabric. The superhydrophobic fabric boat exhibited a remarkable loading capacity; for a boat with a volume of 8.0 cm(3), the maximum loading was 11.6 or 12.2 g when the boat weight is included. Moreover, the superhydrophobic cotton fabric showed a reasonable durability to withstand at least 30 machine washing cycles. (C) 2010 Elsevier B.V. All rights reserved.