At least eight politicians departed for Taiping Island, or Itu Aba as it is also known, at around 7.20 a.m. local time to visit military facilities and other installations, according to the official Central News Agency
The visit comes eight days after the Permanent Court of Arbitration in the Hague passed a landmark ruling on the South China Sea, finding there was no legal basis for mainland China's claims to a large section of the sea. Taiwan, which split politically from the mainland in 1949, also claims much of the same territory.
In its ruling, the court found that Taiwan's Taiping Island was legally a "rock," and did not convey a much-desired Economic Exclusive Zone in the seas around it.
The ruling -- which President Tsai Ing-wen
has rejected -- severely weakens Taiwan's claims to resources such as fish, oil and gas in the South China Sea.
On July 13, immediately after the verdict, Taiwan dispatched a warship to patrol the region -- seven days later, a delegation touched down on Taiping Island.
On Wednesday, Kuomintang party legislator Johnny Chiang posted a photo on Facebook announcing they were "ready to depart", while Democratic Progressive Party (DPP) legislator Lo Chih-cheng wrote, "all aboard, departing to Taiping Island."
Joining the lawmakers on their trip were five Taiwanese fishing boats bearing banners and slogans such as "Safeguard fishing rights in the South China Sea," who departed at about noon on Wednesday for the island, according to CNA
Chiang later confirmed they had successfully landed on Taiping Island and boosted the morale for stationed troops. He told CNA that Taiping Island was definitely an island.
Taiwan's claim in chaotic sea
The South China Sea is one of the world's most politically sensitive regions
, where overlapping claims by at least five countries often lead to tense standoffs.
Taiping Island, for example, is also claimed by China and the Philippines, among others.
To cement their stance, Taiwan has stationed troops and coast guard on Taiping Island
, as well as building a lighthouse, chicken coops, vegetable gardens and military fortifications.
Taipei wanted the Permanent Court of Arbitration to declare the territory an island under international law, granting Taiwan a 200 meter Economic Exclusive Zone which would have given them control over all resources within the area.
Instead, it was declared a legally a "rock," which provides no economic benefits and has led Taiwan to declare the ruling void, a rare point of agreement with Beijing.
Taiwan is not the only player moving to assert their authority following the Hague ruling -- China will hold military maneuvers from July 19
, following an emergency military drill just two days after the verdict was handed down.