Iceberg B15A From the Ship
Typically a tabular berg rises about 130 feet from the sea surface and has a draught of about 700 feet (40m and 213m respectively). With sides that can go on for tens of miles, they make the biggest and most powerful ships appear like little insects buzzing around next to them. B15 at 300km long by 40km wide (186 x 25 miles) represented about 50-100 years of advancement by the part of the ice-shelf that it calved from.
Photo; © Mike Usher - Pictures from an icebreaker cruise to Eastern Antarctica.