RIASSUNTO
Glass housings have been used since antiquity. Glass was the fabled hull material of choice for Alexander the Great's descent into the Mediterranean Sea in 332BC. Fishermen around the world have used glass fishing floats to support their nets since at least 1840, beginning in Scandinavia. Today, glass spheres find application in all the main classes of undersea vehicles: AUVs, Landers, ROVs, and manned submersibles.