How to capture a ship in total war 2

Before i explained how to capture the ship . in Napoleon total war . now i show how to kill the people in the ship and capture it easy .

we have three gun shot types 

first round gun shot that it would destroy the enemy ship and guns

two chain shot witch used to aim the sails and the third is the grape shot that used to kill enemy soldiers on the rival ship as shown as below you would need it several times to kill as much as you need . otherwise you are too lucky .