Blue Sea Systems
Marine circuit protection, fuse holders, battery switches, busbars, and electrical distribution components designed for dependable boat systems.
Blue Sea Systems develops dependable AC and DC electrical products for marine and specialized vehicle applications. The brand is known for practical solutions across circuit protection, power distribution, switching, and system monitoring. The Common Ground Marine selection currently focuses on Blue Sea Systems marine fuses and fuse holders, including ANL, MEGA, MAXI, Class T, and MRBF formats. Compare voltage, amperage, fuse style, and holder compatibility to protect the complete electrical circuit.
Products from Blue Sea Systems
206 products
Blue Sea SystemsBlue Sea Systems ST CLB Circuit Breaker Block - 6 Position with Negative Bus
ST CLB Circuit Breaker Block - 6 Position with Negative Bus. Quick connect clips allow circuit breakers to snap easily into place. Tin-plated copper busses and screw terminals.
SKU BLUE-5052
$66.50MSRP $79.80
Blue Sea SystemsBlue Sea Systems ST CLB Circuit Breaker Block 12 Position with Negative Bus
12-position resettable circuit breaker block with an integrated negative bus, 100A total / 32A per circuit, 32V DC max. CLB breakers sold separately.
SKU BLUE-5054
$113.40MSRP $136.08
Blue Sea SystemsBlue Sea Systems ST CLB Circuit Breaker Block Jumper
Snap-in jumper for Blue Sea ST CLB Circuit Breaker Blocks. Bridges a position to the common source bus in place of a breaker. Sold 5 per package.
SKU BLUE-5049
$7.70MSRP $9.24
Blue Sea SystemsBlue Sea Systems ST Glass 6 Circuit Fuse Block with Cover
6-circuit 3AG glass fuse block with cover, 100A total / 30A per circuit, 32V DC max. Accepts AGC, MDL, and other glass fuses, sold separately.
SKU BLUE-5018
$39.20MSRP $47.04
Blue Sea SystemsBlue Sea Systems ST Glass 6 Circuit Fuse Block with Negative Bus and Cover
6-circuit 3AG glass fuse block with an integrated negative bus and cover, 100A total / 30A per circuit, 32V DC maximum. Fuses sold separately.
SKU BLUE-5015
$46.20MSRP $55.44
Blue Sea SystemsBlue Sea Systems ST-Blade Water-Resistant Fuse Block
IP66 water-resistant ST Blade fuse block, 4 circuits, 80A total / 25A per circuit, 32V DC maximum. Fuses and circuit breakers sold separately.
SKU BLUE-5056
$47.60MSRP $57.12
Blue Sea SystemsBlue Sea Systems SafetyHub 100 Fuse Block
Ignition-protected fuse block consolidating 7 circuits (1-200A), 280A combined max, IP66. Includes ATO/ATC connector plug. Fuses sold separately.
SKU BLUE-7725
$161.00MSRP $193.20
Blue Sea SystemsBlue Sea Systems Solenoid ML 12V
Solenoid ML 12V. For applications where sustained control signals are needed to emulate a Normally Open relay with a lower current draw. Silver alloy contacts provide high reliability for switching live loads.
SKU BLUE-7718
$210.00MSRP $252.00
Blue Sea SystemsBlue Sea Systems Standard CableCap Large Pair
Standard CableCap pair (black and red), for batteries with marine adaptor terminals already installed, fits heavier 1/0 and 2/0 AWG cable sizes.
SKU BLUE-4006
$5.60MSRP $6.72
Blue Sea SystemsBlue Sea Systems Standard CableCap Small Pair
Standard CableCap pair (black and red), for batteries with marine adaptor terminals already installed, fits smaller cable sizes 1, 2, and 4 AWG.
SKU BLUE-4005
$5.60MSRP $6.72
Blue Sea SystemsBlue Sea Systems Terminal Block 20A - 10 Circuit
10-circuit terminal block, 20A continuous rating, 300V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2410B
$9.37MSRP $11.24
Blue Sea SystemsBlue Sea Systems Terminal Block 20A - 2 Circuit
2-circuit terminal block, 20A continuous rating, 300V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2402B
$2.75MSRP $3.30
Blue Sea SystemsBlue Sea Systems Terminal Block 20A - 4 Circuit
4-circuit terminal block, 20A continuous rating, 300V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2404B
$3.67MSRP $4.40
Blue Sea SystemsBlue Sea Systems Terminal Block 20A - 6 Circuit
6-circuit terminal block, 20A continuous rating, 300V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2406B
$5.50MSRP $6.60
Blue Sea SystemsBlue Sea Systems Terminal Block 20A - 8 Circuit
8-circuit terminal block, 20A continuous rating, 300V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2408B
$6.53MSRP $7.84
Blue Sea SystemsBlue Sea Systems Terminal Block 30A - 10 Circuit
10-circuit terminal block, 30A continuous rating, 600V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2510B
$11.07MSRP $13.28
Blue Sea SystemsBlue Sea Systems Terminal Block 30A - 12 Circuit
12-circuit terminal block, 30A continuous rating, 600V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2512B
$12.82MSRP $15.38
Blue Sea SystemsBlue Sea Systems Terminal Block 30A - 2 Circuit
2-circuit terminal block, 30A continuous rating, 600V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2502B
$4.07MSRP $4.88
Blue Sea SystemsBlue Sea Systems Terminal Block 30A - 4 Circuit
4-circuit terminal block, 30A continuous rating, 600V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2504B
$5.38MSRP $6.46
Blue Sea SystemsBlue Sea Systems Terminal Block 30A - 6 Circuit
6-circuit terminal block, 30A continuous rating, 600V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2506B
$7.88MSRP $9.46
Blue Sea SystemsBlue Sea Systems Terminal Block 30A - 8 Circuit
8-circuit terminal block, 30A continuous rating, 600V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2508B
$9.55MSRP $11.46
Blue Sea SystemsBlue Sea Systems Terminal Block 65A - 10 Circuit
10-circuit terminal block, 65A continuous rating, 600V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2610
$28.00MSRP $33.60
Blue Sea SystemsBlue Sea Systems Terminal Block 65A - 2 Circuit
2-circuit terminal block, 65A continuous rating, 600V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2602
$9.10MSRP $10.92
Blue Sea SystemsBlue Sea Systems Terminal Block 65A - 4 Circuit
4-circuit terminal block, 65A continuous rating, 600V AC/DC max. Closed-back design, each screw pair is one isolated circuit. Jumpers sold separately.
SKU BLUE-2604
$12.60MSRP $15.12
Choose the right Blue Sea Systems fuse
Start with system voltage, expected continuous current, conductor size, and the manufacturer's specified overcurrent protection. Then select the fuse family, amp rating, and a compatible holder or terminal block. Match the fuse to the holder and confirm the available interrupt rating and installation clearances.
Browse circuit protectionMarine circuit protection starts with the whole DC system
Blue Sea Systems offers several fuse formats for different installation and service requirements. Compare the electrical specification, physical format, and mating holder before ordering a replacement or building a new system.
- ANL, MEGA, MAXI, Class T, and MRBF fuse formats
- Fuse holders and terminal solutions for organized power distribution
- Guidance on voltage, amperage, conductor sizing, and compatibility
Frequently asked questions
What does Blue Sea Systems make?
Blue Sea Systems designs AC and DC electrical products for marine and specialized vehicle applications. The current selection includes marine fuses and a fuse holder for circuit protection and power distribution.
How do I choose a Blue Sea Systems marine fuse?
Confirm the system voltage, required amperage, conductor size, fuse type, holder compatibility, and the protection requirements specified by the equipment manufacturer. The fuse must be appropriate for the complete circuit, not just the load.
What is the difference between ANL, MEGA, MAXI, Class T, and MRBF fuses?
These are different fuse formats with different physical sizes, holders, ratings, and installation requirements. Use the product documentation and your system design to select the correct format and verify that the fuse and holder are a compatible pair.
Need a quote on Blue Sea Systems gear?
Tell us what you're building. Our team will spec the right kit for your install and send a written quote.
Why buy from us
We carry this brand because it earns its place on the boat.
Stocked for marine builds
We focus on parts that meet the conditions boats see — not just whatever ships fastest.
Engineering review on request
Send a parts list or a layout and we'll check it against your boat before you order.
Direct from our team
Pricing, availability, and product questions all go through the same people who build custom harnesses and panels.