Complex sentence: On the outbreak of World War I, "Laconia" was converted into an armed merchant cruiser in 1914 and based at Simon's Town, South Africa in the South Atlantic, from which she patrolled the South Atlantic and Indian Ocean until April 1915.
Split into simpler sentences: On the outbreak of World War I, "Laconia" was converted into an armed merchant cruiser in 1914. She was based at Simon's Town, South Africa in the South Atlantic, from which she patrolled the South Atlantic and Indian Ocean until April 1915.