The Collaborative International Dictionary of English v.0.48:
Shelvy \Shelv"y\, a. Sloping gradually; shelving. [1913 Webster] The shore was shelving and shallow. --Shak. [1913 Webster]WordNet (r) 3.0 (2006):
shelvy adj 1: full of submerged reefs or sandbanks or shoals; "reefy shallows"; "shoaly waters" [syn: reefy, shelfy, shelvy, shoaly]