Complex sentence: Due to the strong winds and the inaccurate sight most of the Swedish projectiles ricocheted past the Russian ships, that were anchored within the protected area of the harbor, and could use their guns much more effectively.
Split into simpler sentences: Due to the strong winds and inaccurate aiming most of the Swedish projectiles ricocheted past their targets. The Russian ships that were anchored within the protected area of the harbor were able to use their guns much more effectively.