Final Mission of Battleships: A Beginning of Hope for New Lives
Authors: Cheencharoen Bussaban , Thongchavee Suphachittra , Tangthienkul Sasithorn , Pongjit Supphapong , Sujirachato Piyawat 
Published: February 2023

Abstract

Objective/Scope
The H.T.M.S Underwater Learning Sites Project is initiated in 2010 with the main objectives to rehabilitate marine ecology by reusing the decommissioned battleships, namely H.T.M.S. Prab and H.T.M.S. Sattakut, as a new home of marine life and sessile organisms, to enrich the marine biodiversity, to be the learning sites of marine life in long-term basis, and to create new diving sites to attract the tourists, reduce the effects on natural coral reefs from harmful activities such as tourist boat anchoring or mooring onto them, scuba diving damage by touching or stirring up sand sediments, as well as generate a considerable income for local communities.

Methods, Procedures, Process
PTTEP has engaged government agencies, academic institutions, local businesses, and communities to consider the most suitable structure to be used as a new underwater learning site. In 2011, after studying man-made reefs and ensuring the minimal impact on marine ecology, two decommissioned ships offered by the Royal Thai Navy were placed underwater at Koh Ngam Noi and Koh Tao in southern Thailand, the world's famous scuba diving destinations. The underwater ecosystem and biodiversity study has also been conducted before and after the installation of two ships including the study on environmental impact, marine biodiversity, and impact on natural coral reefs.

Results, Observations, Conclusions
The study in 2018 showing the increasing number of small fish from 10 species in 2011 to more than 60 species that reflected the increasing of marine ecology and biodiversity. A recent study shows that these man-made diving sites helped reducing number of touching coral reefs for 16,058,800 times since 2014. Moreover, there was no significant impact on the conditions of the seabed in every area studied. The number of tourists and divers are growing up 37.7% at Koh Ngam Noi, Chumphon province and 18.8% at Koh Tao, Surat Thani province which were able to boost community's economy. The project has generated income to local communities with more than 413 million THB (12.5 million USD) or 59 million THB (1.8 million USD) annually. In 2017, the project was measured by using Social Return on Investment (SROI) method with the satisfied outcome as 5.34:1 (THB) which means for every 1 THB invested in the program, created 5.34 THB in societal benefit. Moreover, the project has generated positive media exposure through activities with PR value of over 55.7 million THB (1.7 million USD) since 2011, raising awareness on marine ecology conservation and contribution to the company's reputation.

Novel/Additive Information
These battleship-man-made dive sites will be in service for more than 60 years and the study on marine ecology and biodiversity will be continuously conducted from time to time to ensure the sustainability in marine ecology. The achievement of this project benefits to petroleum industry by creating public perception and understanding of man-made reef which could be beneficial to Rigs-to-Reefs, as the sound practice of converting decommissioned offshore oil and petroleum rigs and platforms into artificial reefs.