1n. masses of ice in the sea; ice formed from frozen salt water.
1924  Bitterly cold in winter, Labrador has a short and lovely time when the snow and sea-ice melt. . . .
1946  . . . one of those cracks which generally divides [sic] the inshore ice, anchored to the rocks below, from the main body of floating sea ice.
1952  "When I was your age I'd been to Spain and Italy . . . in schooners and square-riggers . . . and before that I'd been out to the sea-ice five seasons with the swilers."