Starting and ending in Ushuaia (Argentina), ships bound for the Antarctic Peninsula have to cross the dreaded Drake Passage, a trip which is roughly 900 km long. “Rough” would actually be an understatement on a ship rolling about 20° to 30° for two consecutive days. This passage is considered one of the roughest seas in the world. Many people on board were seasick and stayed in their cabins. Not many passengers would show up for the scheduled meals.
It is a well known fact, that most of the iceberg’s volume lies beneath the water. Expressions, such as “I can only see the tip of the iceberg” underline the fact, that most of the iceberg body is hidden under water. And there’s the “Titanic”, which was hit by an iceberg and sank. Reason why in 1914, governments have established an Ice Patrol to monitor iceberg movements.