Designing arcade machines for operation in underwater or high-pressure environments presents a unique set of formidable engineering challenges that extend far beyond standard cabinet construction. The primary and most obvious hurdle is achieving a perfect, permanent seal against water ingress. This requires specialized gaskets, seals, and welding techniques that can withstand immense and fluctuating external pressure without failing, effectively creating a watertight pressure vessel. Every single point of entry, from button plungers and joystick shafts to coin slots and service doors, becomes a critical potential failure point that must be meticulously engineered.

Internally, the extreme pressure itself poses a significant threat. Standard electronic components, including PCBs, monitors, and power supplies, are designed for atmospheric pressure. In a high-pressure environment, air pockets within components can collapse, and materials can behave differently, leading to catastrophic failure. This necessitates either designing the cabinet to internally maintain surface-level pressure—a complex and heavy solution—or utilizing pressure-tolerant components specifically designed for deep-sea applications, which is extremely costly.

Furthermore, the corrosive nature of seawater, especially saltwater, is a relentless enemy. Standard metals will rapidly corrode, and many plastics can degrade. All external materials, from the cabinet's shell to the buttons and joystick, must be made from highly corrosion-resistant materials like specific grades of stainless steel (e.g., 316), titanium, or marine-grade polymers. Conductive surfaces are particularly vulnerable to galvanic corrosion, requiring careful material selection and isolation.

Finally, user interaction is severely complicated. Traditional arcade controls rely on precise movements and tactile feedback, which are impeded by water resistance and the potential need for the user to wear gloves or operate from a submersible. Designing intuitive, reliable, and pressure-proof control systems that provide a satisfying gameplay experience is a major human-factor engineering challenge. Overcoming these obstacles requires a multidisciplinary approach, merging marine engineering, materials science, and electronics design, making such specialized arcade machines rare and exceptionally expensive feats of engineering.