A cheap gauge-hole Bluetooth stereo for a jon boat, golf cart or UTV. Its IPX5 rating covers splashes, not heavy spray.
Price checked November 7, 2026. As an Amazon Associate we earn from qualifying purchases.
The rating comes from 7 measured or published factors, each scored 0-100 against fixed reference points for its mount. How we rank explains each one.
| Model number | MGR300B |
|---|---|
| Audio | |
| Zones | 1 |
| RCA output sets | 2 |
| Sources and control | |
| Bluetooth | Yes |
| USB playback | Yes |
| Phone app | No |
| SiriusXM-ready | No |
| NMEA 2000 | No |
| Wi-Fi or AirPlay 2 | No |
| Weather band | No |
| DAB+ | No |
| CD player | No |
| Camera input | No |
| Build | |
| Mount | Gauge hole |
| Front water rating | IPX5 |
A full-featured gauge-hole stereo for a small boat or powersports dash. Spend more on the eXcelon KMR-XM500 only if you want its 5 V pre-outs and longer warranty.
Amazon $299An inexpensive gauge-hole Bluetooth receiver for a golf cart, UTV or small boat, with room to add an amplifier.
Amazon $164.99A basic gauge-hole stereo for a small boat or cart that needs Bluetooth and radio and little else.
Amazon $157.38Compare the BOSS Audio MGR300B with any other marine stereo →
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