Complex sentence: Downtown Santa Marta is also building its own international marina planned for completion in 2011, which will be attractive to international sailing boats especially during the hurricane season due to shelter from the surrounding mountains.
Split into simpler sentences: Downtown Santa Marta is also building its own international marina, planned for completion in 2011. In this way Santa Marta hopes to attract international sailing boats, especially during the hurricane season, since Santa Marta is protected from hurricanes by the surrounding mountains.