This paper presents an operational comparison of two open source-based control platforms for a practical, low cost do-it-yourself underwater remotely operated vehicle (ROV) developed by Underwater Technology Research Group (UTeRG), Universiti Teknikal Malaysia Melaka. Research institutes and hobbyist have shown a growing interest in the development of observation class remotely operated vehicle using open-source platform. Two low-cost open-source solutions for such ROV are known as OpenROV, an open-source platform that is introduced by OpenROV company, and the Ardusub, an open-source ROV kit promoted by Blue Robotics Company. Both open-source hardware and software platforms are being used worldwide for the development of small range of electrical powered ROV system's architecture, with support from the literature in the internet and the extensive experience acquired with the development of robotic exploration systems. The comparison of both open-source platform is discussed in detail, to provide guidance on how to build our own do-it-yourself ROV, with the lowest possible cost.