## 3 Materials and Methods  
### Hardware and Software  
For this trial, we used a Meta Quest 2 (256 GB) VR headset and four equivalent VR headset devices with touch controllers, which is developed by the company Meta, formerly known as Facebook, based in Menlo Park, CA, USA. However, the VR simulator cannot be supported by the headset alone due to its limited hardware resources and the requirements of the simulator. Therefore, each of the four VR headsets was wirelessly connected to its own computer with a dedicated graphics card to run the VR simulator while receiving controls and sending rendered video from the VR headset wirelessly. Each computer had its own dedicated wireless connectivity card, allowing it to create a wireless hotspot for each VR headset to connect to, minimizing lag and maximizing bandwidth to maintain satisfactory video and response quality. The VR laboratory, the used equipment, and the familiarization of the trial participants can be seen in Figure 1.  
Two of the computers used had an identical configuration, including a 13 th Gen Intel Core i7-13700F (2.10 GHz) CPU, 32 GB DDR5-4800 (2400 MHz) RAM, and a NVIDIA GeForce RTX 4070 Ti 12 GB VRAM GPU. The third computer was equipped with a 13 th Gen Intel Core i7-13700F (2.10 GHz) CPU, 32 GB DDR5-4800 (2400 MHz) RAM, and a NVIDIA GeForce RTX 3080 10 GB VRAM GPU. The fourth computer featured a 12 th Gen Intel Core i7-12700F (2.10 GHz) CPU, 8 GB DDR4-2400 (1200 MHz) RAM, and a NVIDIA GeForce RTX 4070 Ti 12 GB VRAM GPU. All computers ran 64-bit Windows 10 Pro Version 22H2 and were equipped with an Intel Wi-Fi 6E AX210 160 MHz wireless card.  
The VR simulator, called VR engine room, is created using 3D modelling software Blender 4.2 and Unreal Engine 5.4. It is specifically designed for use with Windows computers and it is compatible with a variety of VR HMDs, both wired and wireless.  
Some of the features of the VR simulator are X-ray vision, which allows users to peer inside equipment by moving the housing; realistic object manipulation; and interaction with various objects such as starting engines, measuring cylinder pressure, manipulating valves, and using a fire extinguisher, as seen in Figure 2.  
The simulator also includes simulation scenarios for fire, flood, blackout, and evacuation. Participants in the simulation are tasked with performing several activities, including using X-ray vision to inspect equipment interiors (by moving the housing), manually  
Figure 1: Depiction of the VR laboratory, equipment, and the familiarization of the participants.  
Figure 2: Some of the possible interactions possible in the simulator (e.g., engine start, fire extinguisher use, blackout flashlight).  
operating equipment and interacting with objects, using a fire extinguisher, and navigating through the virtual environment, as seen in Figures 3-5.  
A ship engine room model was created based on actual blueprints of an RO-RO ship; it is double-decked and measures 16.1 \(\times\) 19.6 m. On the bottom deck, it has two main four-stroke diesel engines with shaft generators, three diesel generators, propeller shafts, cooling systems for sea and fresh water, pumps, valves, and pipelines. The upper deck has two heavy fuel oil purifiers, one diesel oil purifier, one service air compressor and two start air compressors, fuel and lubricating oil tanks, valves, and pipelines.