Queen Elizabeth prepared for an action-packed final day of a state visit to Malta on Saturday, including a picturesque boat trip around the Mediterranean island she once called home.

The 89-year-old monarch, who arrived Thursday for a three-day visit, will first of all roll up her sleeves to plant a tree in the grounds of the presidential San Anton palace, an exotic oasis in the heart of the country.

The gharghar sapling -- a small cypress which is Malta's national tree -- will be the first of its kind in the palace's private gardens and will grow next to an olive tree planted 10 years ago by the queen during her last state visit in 2005.

The monarch lived in Malta between 1949 and 1951 as a princess with her new husband Prince Philip, who was stationed on the island as a Royal Navy officer.

It was reportedly the happiest time of their lives and the pair have returned several times over the years -- most recently in 2007 to celebrate their diamond wedding anniversary.

The couple will visit the Heritage Malta centre which conserves the country's historical sites, including temples dating back over 5,000 years which folklore has it were built by giants.

The centre, where the national art collection is also preserved and restored, is housed in the former Bighi Hospital, a major navy infirmary that served a vast area from 1832 until 1970, giving Malta the nickname "The Nurse of the Mediterranean".

The hospital tended to casualties of the first and second world wars, and the then-princess paid tribute to their service in 1949, visiting patients here on Christmas Eve.

- Racing sulkies -

It was a hugely independent time for the future queen, who used to beetle around the island in her own car.

She also took to the waves in a Maltese traditional taxi boat -- a dghajsa -- commissioned by the Royal Navy to ferry her around. And she will be hopping back in one later Saturday.

Queen Elizabeth and Prince Philip will do a tour of Valletta's harbour in a dghajsa built in 1954, sailing in front of Britain's HMS Bulwark assault ship as a 21-gun royal salute rings across the bay.

The cannons will fire from the Barrakka gardens on the sea front, where the princess, then in her early 20s, used to come and wave in the navy fleet.

The crew of the British ship -- which has played a significant part in rescuing boat refugees in the Mediterranean -- will perform a royal salute as the sovereign sails past.

The horse-loving monarch will spend her last hours here at the Marsa racecourse, where she reportedly used to come to ride but also to dance the night away at an on-site club.

The racecourse and polo club was founded in 1868 by naval officers and dedicated to flat racing until 1940, when racing in sulkies was introduced and took the public by storm.

The queen is likely to have wiled away many a happy Saturday afternoon cheering on sulkies -- light two-wheeled, single-driver horse-drawn carts used chiefly in trotting races.

The royals will view trotting races and the final chukka of a polo match at the club -- the second oldest polo club in the world -- before awarding prizes to the victors.

They will then set off for the airport in cars from the 1950s -- Austin Princesses with leather seats and walnut wood interiors -- in a final nod to a bygone age of liberty.