Where the culture equipment are kept off the bottom.
O'sullivan, D., Hilder, M. & Rough, K. (comp.) (1996) A dictionary of aquaculture. A guide to commonly used words and terms. Aquaculture Sourcebook, (6):64p. Launceston, Tasmania, Univ. Tasmania Key Centre for Aquaculture/ Turtle Press Pty Ltd., 2nd. Ed