If you want dedicated underwater audio with massive storage for serious lap training, choose SEWOBYE Waterproof MP3; if you need versatile open-ear safety and wireless freedom for mixed-sport routines, choose Rhyfell Bone Conduction Swimming.
• SEWOBYE: Delivers true underwater listening with 16 hours of playtime and 8GB storage, but requires wired earbuds that can feel restrictive for non-swimming activities. Best for the swimmer who wants zero distractions in the pool.
• Rhyfell: Offers bone conduction technology to keep ears open for ambient awareness and includes Bluetooth 6.0 for phone-free wireless use, though its battery life is shorter at 10 hours. Best for the athlete training across land and water who prioritizes situational awareness.
The SEWOBYE unit is built with a singular, uncompromising focus: it is the best waterproof mp3 player for the lap or marathon swimmer. Its design philosophy centers on eliminating the friction between your gear and your music. The device itself is incredibly compact, measuring just 0.75 inches deep by 2.01 inches high, making it light enough to clip directly onto goggle straps or swimsuit bands without adding bulk. This small footprint means you won't feel weighed down during long sets, allowing you to focus entirely on your stroke count and pace.
What truly sets this device apart is its commitment to sound fidelity under pressure. Unlike many entry-level swimmers' players that muffle audio, this unit supports lossless formats like FLAC and APE, ensuring that HIFI quality remains intact even when submerged. The IPX8 rating confirms it can withstand submersion up to 10 feet (3 meters), providing total peace of mind during deep dives or vigorous splashing. The control buttons feature raised ridges specifically engineered for wet fingertips, so you can change tracks or adjust volume without ever needing to look down or fumble with slippery plastic.
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-28 · 6 min read · Independent comparison
This product is ideal for athletes who treat swimming as their primary workout and demand reliability above all else. If you are someone who needs to listen to audiobooks or large music libraries while in the water, the 8GB memory capacity holds over 2,000 songs, removing the need to constantly sync a phone. However, it is not for everyone. The reliance on short-cord headphones means you must be comfortable with a physical tether. While the included extension cord helps for dry activities, the wired nature limits versatility for running or cycling where wireless freedom is often preferred. If you hate wires or need to hear traffic around you while moving outdoors, this specialized tool might feel too restrictive.
The Rhyfell Fit 5 takes a different approach by leveraging bone conduction technology to create an open-ear experience. Instead of sealing your ear canal, this device sits comfortably on your cheekbones, transmitting sound through vibration. This design is crucial for safety and awareness during outdoor activities. Whether you are surfing, running, or swimming, you remain aware of your surroundings because your ears stay completely open to ambient noise. The ergonomic frame weighs only 28 grams, utilizing liquid silicone to ensure a secure fit that stays stable even during high-intensity movements like triathlon training or aggressive kicking in the pool.
For the athlete who transitions between disciplines, the dual-mode capability is a game-changer. You can switch seamlessly between MP3 mode for underwater use and Bluetooth 6.0 for surface activities. The Bluetooth 6.0 chip promises instant pairing and zero-delay syncing, which is essential for keeping audio perfectly aligned with your movement when running or walking. With a massive 32GB internal storage, you can load over 8,000 songs directly onto the device, meaning you never need to carry your phone into the gym or pool. The battery life supports up to 10 hours of continuous playback, which is sufficient for most full-day adventures from sunrise marathons to sunset hikes.
This product fits the multi-sport enthusiast who values versatility and safety. It is perfect for those looking for comfortable open ear headphones for exercise where hearing the environment is just as important as the music. However, the trade-off lies in the battery life and underwater performance compared to dedicated players. While it handles submersion up to 2-5 meters effectively, the 10-hour battery life is half that of some competitors designed strictly for endurance swimming. Additionally, the open-ear design means bass response will naturally differ from sealed earbuds, which might not satisfy purists seeking absolute isolation from the outside world.
• Best for battery life → SEWOBYE Waterproof MP3, offering up to 16 hours of playtime versus 10 hours on the Rhyfell.
• Best for storage capacity → Rhyfell Bone Conduction Swimming, holding 32GB for over 8,000 songs compared to 8GB for roughly 2,000 on the SEWOBYE.
• Best for underwater isolation → SEWOBYE Waterproof MP3, using traditional sealed earbuds for superior sound separation in the pool.
• Best for situational awareness → Rhyfell Bone Conduction Swimming, thanks to its open-ear design that lets you hear traffic and coaches.
• Best for connectivity flexibility → Rhyfell Bone Conduction Swimming, featuring Bluetooth 6.0 for wireless pairing with phones on land.
• Best for wet-surface controls → SEWOBYE Waterproof MP3, with raised button ridges specifically designed for easy operation with wet fingers.
• Best for lightweight comfort → Rhyfell Bone Conduction Swimming, weighing only 28g with a liquid silicone frame for all-day wear.
• Best for audiobook lovers → SEWOBYE Waterproof MP3, supporting a wide range of formats including APE and FLAC for high-quality narration.
In my opinion, if I were preparing for a rigorous swimming session or a triathlon, I would choose the SEWOBYE Waterproof MP3. The combination of 16 hours of battery life and the ability to store thousands of songs makes it the superior tool for dedicated aquatic training. The raised buttons and secure clip design show a clear understanding of the specific pain points swimmers face, such as losing track of controls or dealing with tangled cords. While the Rhyfell is an excellent piece of hardware for its versatility, the SEWOBYE's focused engineering delivers a more reliable experience for the core use case of exercise in the water. For anyone serious about swimming, the extra battery life and superior underwater audio clarity make it the smarter investment.
Both units are built for durability with high waterproof ratings, but the SEWOBYE is rated IPX8 for deeper submersion, while the Rhyfell uses IP68 protection against dust and water. Both feature materials designed to withstand heavy sweating and chlorinated water environments.
Neither device is explicitly marketed as a "sleep headphone" or primarily for calls, as both focus on music playback during activity. The Rhyfell allows for wireless connection via Bluetooth 6.0, while the SEWOBYE relies on direct wired connections, making call functionality less relevant to their primary design.
The Rhyfell offers an open-ear design that blends music with ambient sound, which is safer for outdoor running. The SEWOBYE provides isolated, high-fidelity audio through sealed earbuds, which blocks out external noise but may reduce environmental awareness during land-based workouts.
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