Blue Sea dual USB chargers let you add charging connections to a suitable boat or RV electrical panel. The 1016 offers 2.1 amps total while the 1039 and 1045 offer 4.8 amps total; however, the 1039 fits a rectangular switch opening and the other two fit a round socket hole. Compare the shape and electrical rating before selecting a model.
Round outlet hole versus Contura switch aperture
1⅛-inch (approximately 28.6 mm) hole. The models share the mounting shape but have different rated USB charging outputs.
Approximately 0.83-inch wide × 1.45-inch high. Check the full Contura switch opening before replacing an existing fitting.
Cutout illustrations are simplified and not to scale. Confirm the manufacturer's mounting drawing and rear clearance before cutting or enlarging a panel.
Blue Sea dual USB charging and mounting comparison
All three current models provide 5V DC USB charging and are listed for 12/24V electrical systems. The output-current values below are combined totals for both ports, not per-port ratings.
| Base MPN | Mounting style | Panel opening | Maximum total output | Supply range | Idle draw |
|---|---|---|---|---|---|
| 1016 | Round socket hole | 1⅛ in (28.6 mm) diameter | 5V, 2.1A total | Current model: 9–32V DC | 15 mA |
| 1039 | Rectangular Contura switch hole | 0.83 in W × 1.45 in H | 5V, 4.8A total | 9–32V DC | 1 mA |
| 1045 | Round socket hole | 1⅛ in (28.6 mm) diameter | 5V, 4.8A total | 9–32V DC | 1 mA |
Manufacturer current-version figures are 9–32V DC for all three chargers. The earlier 12V-only 1016 revision was rated for 9–16V DC. Inspect the actual product label before connecting a replacement to a 24V system.
Installation and charging considerations
Install on an appropriately protected DC circuit with the polarity and fuse arrangement specified by Blue Sea. Allow space for the rear connectors and cable bends, and keep the protective cap closed when the USB ports are not in use.
1016 is rated at 2.1A total across its two ports. The 1039 and 1045 are rated at 4.8A total and use intelligent device recognition. None of these ratings means each port supplies the full combined output, and these USB-A chargers are not USB-C Power Delivery units.
Blue Sea lists an IP45 rating with the protective cover closed. An open charging port should not be treated as watertight.
Blue Sea dual USB charging outlets
Select the matching charger to review the complete listing and current availability.

Blue Sea 1016
Two USB charging ports in a round dash socket. The original 12V-only revision was replaced by a 12/24V version.
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Blue Sea 1039
Two USB charging ports in a rectangular switch-shaped housing for a Contura switch aperture.
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Blue Sea 1045
A higher-output dual USB charger with intelligent device recognition, fitted into a common round dash socket hole.
View charger details and availabilityRelated marine DC electrical parts
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