In depth
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At a glance
The Boom 3i is unusually focused on where it will be used. Its upright floating design, saltwater-resistance claims and IP68 rating make water-based outings a clearer reason to buy it than the usual promise of portable bass. The included strap and 780 g weight also keep it within ordinary day-bag territory.
The tradeoffs are straightforward. It relies on Bluetooth for music, does not charge a phone, and benefits from time spent adjusting the sound.
Soundcore gives the Boom 3i a 50 W rating and a bass enhancement mode, but its app is the more important tool for shaping the result. SoundGuys found the default sound dark and improved treble clarity with the nine-band equalizer. 1 That suggests starting with a familiar track and making a small adjustment before deciding whether the stock preset suits you.
One speaker plays mono. A pair can serve a more deliberate stereo setup, though a single cabinet is often the practical choice when listeners and watercraft are moving. Bass boost also affects the battery load, so the strongest low-end setting and the longest runtime belong to different use cases.
Bluetooth supports SBC and AAC, and the speaker can stay connected to two source devices. That is useful when two people share music without repeatedly starting the pairing process. An analog source has no AUX route, which is worth checking if a player or projector is part of the plan.
TWS and PartyCast extend playback to compatible speakers. PartyCast uses a main speaker to control the group, and lighting on different models does not necessarily synchronize. The app also offers voice-clip amplification, but the support guide limits it to recorded clips. It does not provide live microphone reinforcement. That distinction matters for anyone imagining it as an announcement system.
The 16-hour manufacturer test uses default EQ, 50% volume and both lighting and BassUp disabled. This gives a realistic explanation of how to prioritize endurance during a long day. Turning on the effects or raising the volume moves away from that test condition.
A 15 W, 5 V/3 A supply is recommended for a roughly four-hour charge. The USB-C connection charges the speaker but does not provide a phone power bank, as SoundGuys also notes. 1 Keep a separate phone-charging plan if navigation and streaming will use the same device throughout the outing.
The floating arrangement is more useful than buoyancy alone because it is designed to keep the speaker oriented for playback. It still makes sense to secure the speaker when the water is moving. Recovery convenience and keeping music pointed toward the group are separate benefits from an ingress rating.
Soundcore also claims a one-meter drop test and enhanced saltwater durability. The port cover must be closed, and cleaning and drying remain part of owning any speaker used around sand or seawater. The app’s Buzz Clean function adds a cleaning aid, while the strap gives a convenient way to carry the speaker between dry and wet parts of the trip.
The smaller Boom Go 3i adds a battery display and phone-charging output in a compact strap-equipped format. Choose the Boom 3i when floating orientation and the larger sound system are more relevant. The models use different speaker-linking features, so family branding alone is not a reason to assume they will join the same group.
The Boom 3i is a convincing feature match for frequent water-side listening, especially for someone willing to adjust EQ. Its design gives it a specific purpose. A buyer who mainly wants a desk speaker, wired input or power bank can spend more directly on those priorities elsewhere.
This is a research-based review. The Fasit has not physically tested this product.
Independent sources cited in this article.
Reviewer found default tuning dark and improved clarity with the nine-band EQ. Speaker cannot charge phones and plays mono alone.