Leonor, seven and her six-year-old sister Sofia completed a sailing course at the National School of Vela Calanova in Palma de Majorca, where Felipe has been participating in the race, as he does very year.
The girls' mother Princess Letizia proudly looked on as her daughters collected their diplomas from their Queen Sofia, who warmly embraced her grandchildren.
CLICK ON PHOTO FOR FULL GALLERY
Leonor and Sofia were surrounded by their six cousins and aunt, Infanta Elena at the event which signals the start of the family's annual holiday in Majorca.
As well as Elena's son and daughter, Felipe, 15, and Victoria, 12, her sister four children Juan, Pablo, Miguel and Irene also joined the group without their parents. Infanta Cristina is busy preparing to move to Switzerland after facing charges for a corruption scandal involving her husband Iñaki Urdangarin.
Stylish Princess Letizia wore a pair of yellow trousers and a white t-shirt, adding a pair of sparkly summer sandals while Elena protected herself from the sun with trilby hat and sported a pink polo shirt tucked into beige trousers.
Elena and her mother Sofia were first to arrive on the island for the royal's yearly vacation after Sofia and Felipe attended an engagement in the fire ravaged town of Andratx.
Upon her arrival last week King Juan Carlos' wife was spotted in Majorca carrying a cute personalised handbag.
The blue and cream tote featured photographs of her eight grandchildren on it, with Sofia's grandsons, Juan, Pablo and Miguel and Felipe featured on one side of the bag completing the set on the other side of the stylish accessory were her granddaughters Infanta Leonor, Infanta Sofia, Victoria and Irene.
Felipe, Leonor and Sofia get their love of sailing from King Juan Carlos and Queen Sofia, who both competed in Olympics
Sofia represented Greece in the 1960 Olympics in Rome and her husband represented Spain in the 1972 Munich Summer Olympics.
Prince Felipe and his sister Infanta Cristina both followed in their parent's footsteps and competed 1992 Barcelona Olympics and 1988 Seoul Olympics respectively.