The snaps reflect Pierre's personal interests and hobbies. The first showed him aboard the Maserati yacht, his face full of elation as he completed a sailing race.
"Amazing race! #SydneyHobart #sailing #Monaco #Maserati @giosoldini," he wrote.
Beatrice Borromeo and Pierre Casiraghi married last summer
Pierre, who is a member of the Maserati team, has always had an affinity with the sea. His friend Giovanni Soldini is the skipper of the boat and together, the pair and their fellow crew members have sailed from Cape Town to Rio, and San Francisco to Shanghai.
Pierre is on the management committee of the famed Monaco Yacht Club. He also founded the "Sail for a cause" charity race to raise money for underprivileged children. Last year he and his wife Beatrice Borromeo attended a gala for the charity, at the Monaco Yacht Club.
Pierre's first photo showed him aboard the Maserati yacht
The grandson of Hollywood star Grace Kelly is also a keen racer. Pierre is a regular fixture at the Monte-Carlo Historic Rally, a vintage car race that happens every year in January. The petrolhead has also taken part in various races including two in Germany.
Royal watchers are hoping that Pierre will give his 200 plus followers a glimpse at his personal life. The royal married Italian journalist Beatrice last summer in a romantic civil ceremony in Monaco, followed by a larger, even more spectacular wedding on Isola Bella, one of the Borromean Islands on Lake Maggiore owned by Beatrice's family.
Grace Kelly's grandson is also a keen racing driver
The statuesque blonde, who met Pierre at university, welcomed her husband to Instagram. "Welcome to Instagram PierreCasiraghi_official!" she tweeted.
While Pierre has an open account, his wife Beatrice, 30, has a private one. She has more than 1,000 posts on Instagram but is more selective with her followers; just over 200 of her close friends and family members are allowed to follow her.