CHASING M2 S Underwater ROV (656’ Tether): The Industrial Workhorse Review

The CHASING M2 S is not a recreational drone; it is a serious, industrial-grade Remote Operated Vehicle (ROV) designed for professionals, commercial inspectors, and demanding hobbyists who require exceptional maneuverability, modularity, and depth capability. Positioned as an upgrade to the original M2, the M2 S refines its core technologies with the goal of creating a more stable, powerful, and reliable underwater platform, particularly when operating in challenging conditions.

The specific configuration being reviewed—the Standard Set with the 200m (656-foot) tether—is the workhorse option, providing the maximum depth rating and the necessary reach for complex infrastructure inspections, deep-water surveys, aquaculture monitoring, and search and recovery operations.

Core Philosophy: Open-Body Modularity and C-Sense Control

The fundamental difference between the CHASING M2 S and many of its competitors is its open-body design. While some drones use a compact, sealed cage structure, the M2 S adopts a streamlined, butterfly-wing-outlined frame (380 x 267 x 165 mm, weighing 4.5 kg). This design isn’t just aesthetic; it’s a deliberate choice to enhance modularity and accessory compatibility. The frame is engineered to easily accommodate over 20 professional attachments, including sonars, laser scalers, external cameras, and multi-functional grabber arms, without requiring complex modifications.

Driving this modular frame is the advanced C-Sense Control System, which combines three key proprietary mechanisms:

1. NeptuneX Intelligent Flight Control System: This is the brains of the operation. It uses an internal navigation algorithm to maintain the ROV’s heading and depth with high precision, actively compensating for external interference like strong currents or wave action. This allows for stable hovering (posture lock) and accurate linear movement, which is crucial for detailed inspection work.
2. Eight Vectored Thrusters: The M2 S maintains CHASING’s signature 8-thruster symmetrical vector arrangement. This layout provides full omni-directional movement (360°), meaning the ROV can translate horizontally (forward, back, left, right) and rotate (yaw, pitch, roll) independently. This independence is paramount for professional tasks where precise positioning—such as moving laterally along a hull while maintaining a steady camera angle—is required.
3. Apex Anti-Stuck C-Motor 3.0: Recognizing that motor failure due to debris or corrosion is a major pain point in underwater robotics, CHASING equipped the M2 S with its third-generation thruster technology. The C-Motor 3.0 features a new anti-stuck technique and magnet protection to significantly reduce electrochemical corrosion in saltwater environments and prevent motor jams from sand and fine particles.

Detailed Technical Specifications (656′ Tether Standard Set)

Camera and Imaging System

The CHASING M2 S comes equipped with a capable imaging system centered around a 1/2.3-inch Sony CMOS sensor, capturing 12MP still images and 4K UHD video at 30 frames per second. While this sensor size is common in high-end action cameras, CHASING differentiates itself through its software processing and illumination:

• Aquavision Image Algorithm: The ROV utilizes a proprietary color restoration algorithm designed to correct the severe color loss and distortion that occurs in the blue-green underwater spectrum. This advanced processing helps the footage retain more accurate colors, clarity, and contrast, especially in deeper, less-illuminated environments.
• Illumination Power: With dual 2000-lumen LED lights, the M2 S provides a massive 4000 lumens of adjustable light (with three dimming levels). This level of illumination is essential for industrial inspections, where every crack and detail needs to be visible. Furthermore, the light positioning and mounting are designed to minimize backscatter—the reflection of light off water particles—which significantly improves image clarity.
• Storage and Data Offload: A crucial upgrade from earlier models is the removable SD card slot (default 64GB, up to 512GB). This eliminates the need for slow, cumbersome wireless file transfers, allowing professionals to quickly pull large 4K video files after a mission. The controller also features an HDMI output for live streaming or quick review on a larger monitor.

Operational Review and User Experience

The M2 S excels in scenarios that demand precision and stability. The combination of the 8-thruster layout and the NeptuneX control system makes precise maneuvering possible, even for a single operator. The ability to lock depth and heading allows the pilot to focus on the inspection task without constantly correcting the ROV’s position.

Swappable Battery System: One of the M2 S’s most valuable professional features is the quick-swap battery system. The standard 97.68 Wh battery offers up to 4 hours of run time (depending on usage, less with heavy thruster/light use), but the ability to rapidly swap in an optional 200 Wh backup or multiple 97.68 Wh batteries minimizes downtime. For continuous, all-day operations, the optional Shore-Based Power Supply System (C-SPSS) can be utilized, providing uninterrupted AC power.

Tether and Deployment: The 200m (656-foot) tether is robust and provides a massive operational radius. The Standard Set includes a manual reel, simplifying deployment and retrieval, and mitigating the risk of cable management issues—a common source of frustration in tethered ROVs.

User Feedback and Maintenance Considerations:

While the M2 S is a formidable tool, user feedback highlights some trade-offs inherent to its class:

• Saltwater Maintenance: As noted by experienced users, while the new C-Motor 3.0 has anti-stuck features and magnet protection, the open-core nature of these motors means they require diligent maintenance, especially after saltwater use. Thorough rinsing and regular lubrication are mandatory to prevent corrosion and seizing over time.
• Camera Perception: For pure inspection tasks, the 4K EIS camera and Aquavision algorithm are highly effective. However, some professional cinematographers find the onboard camera adequate for navigation and inspection, but not always suitable for high-end film production, sometimes preferring to mount an auxiliary action camera (like a GoPro) to the integrated base.
• Durability and Repairability: The modular, open-frame design, while great for accessories, makes replacing components straightforward. Unlike some sealed units, individual motors, lights, and the battery are designed to be user-swapped, lowering long-term cost of ownership compared to units that require specialized factory service for every issue.
  

Pros and Cons Chart

Competitor Comparison: CHASING M2 S vs. QYSEA FIFISH V6 Expert

The CHASING M2 S’s primary rival in the light-industrial/prosumer tethered ROV market is the QYSEA FIFISH V6 Expert. Both offer 360° movement and 100m depth, but their design philosophies lead to distinct operational differences.

The comparison highlights a clear split:

• Choose the M2 S if: Your mission requires the ability to constantly swap batteries for marathon sessions, you need the independent translational control offered by 8 thrusters, or your application demands the integration of bulky, third-party professional payloads (like advanced sonars) on its open frame. The M2 S is the ultimate customizable toolkit.
• Choose the FIFISH V6 Expert if: Image quality and extreme stability are your highest priority, you need the enhanced visibility provided by 6,000 lumens, or you value the convenience of the AI Vision Lock system for automatically tracking subjects. The V6 Expert is often considered the better choice for cinematography and precise salvage/retrieval when the robotic arm is factored in.

Final Verdict

The CHASING M2 S Standard Set with the 656-foot tether is a top-tier investment for the serious underwater professional. It is the evolution of a successful platform, addressing previous shortcomings with the Apex Anti-stuck C-Motor 3.0 and the enhanced C-Sense flight control.

Its strength lies in its sheer utility and adaptability. The 8-thruster omni-directional maneuverability is flawless for complex positioning, the modular open body is an engineer’s dream for custom payloads, and the swappable battery system ensures the ROV is mission-ready far longer than its integrated-battery counterparts. The 4K camera system is professional-grade for inspection and documentation, especially when bolstered by the powerful 4,000-lumen lights and Aquavision color correction.

While it demands a disciplined maintenance routine, particularly after saltwater use, the M2 S delivers on its promise of being a powerful, flexible, and essential tool for industrial, commercial, and research applications, offering an unparalleled working range with its 200-meter tether.

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