Beginning of the Story
A local cultural promotion association responding to the popularity of the Wang Yeh Boat Burning Festival proposed to apply a Guinness World Record for the largest boat of such ones.  The goal was to attract more attention from domestic worshippers, and also to take the chance to publicize the island’s traditional folk cultural activities to a worldwide audience.  Before the verification of the judges of Guinness World Records, the Association wanted to make some precision measurements with the help of a reputable third-party authority.  CMS, as a national metrology institute, was chosen for the special mission.

Though measurement is CMS’s professionals.  For this special case closely concerned with religion, some main factors were not determined by technical requirements but by the gods.  For example, could the boat be moved for measurement? What time would be appropriate to do the measuring?  Through the religious rituals, the gods gave instruction of the best time to be 18:30 on Dec 31, 2014 – even though this time meant poor environmental conditions for precision measurement, due to the weak late afternoon sunlight.

How to verify the “world’s largest”
Length and weight are two criteria for applying to be the “world’s largest”.

For length measurement
The technical team positioned the control points with closed traverse and circuit leveling technology, and measured with the forward intersection method.  Through data analysis, the size of the boat was determined to be 24.872 m (L) × 5.075 m (W) × 4.752 m (H). 

For weight measurement
A truck served as a carrier for the 24-meter-long boat’s movement, which was equipped with a threeaxis single head and a two-axis chassis, inseparable.  We laid an authorized weighbridge in advance on the movement route and measured it with dynamic method.  Deducting the weight of the carrier, we obtained the weight of the boat to be 29 400 kg. Taiwanese Traditional Folk Culture –