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 PowerBar 600A BusBar Four 3/8in-16 Studs
PowerBar 600A busbar, four 3/8in stud terminals, 545A AC / 600A DC continuous rating. Compact high-amp busing for large DC electrical systems.
SKU BLUE-2104
$110.60MSRP $132.72
Blue Sea SystemsBlue Sea Systems PowerBar BusBar Cover for PN 2104
Clear insulating busbar cover, fits PowerBar 600A BusBar, 4-stud (PN 2104). Snaps on with no tools to satisfy ABYC/USCG insulation requirements.
SKU BLUE-2708
$23.80MSRP $28.56
Blue Sea SystemsBlue Sea Systems PowerPost 1/4in-20 Stud
PowerPost connector, 1/4"-20 stud, 1-1/16" length, 48V DC maximum. Insulated single stud stacks multiple ring-terminal conductors at one connection point. Includes insulator cap.
SKU BLUE-2001B
$12.60MSRP $15.12
Blue Sea SystemsBlue Sea Systems PowerPost 3/8in-16 Stud
PowerPost connector, 3/8"-16 stud, 7/8" length, 48V DC maximum. Insulated single stud stacks multiple ring-terminal conductors at one connection point. Includes insulator cap.
SKU BLUE-2003
$12.60MSRP $15.12
Blue Sea SystemsBlue Sea Systems PowerPost 5/16in-18 Stud
PowerPost connector, 5/16"-18 stud, 7/8" length, 48V DC maximum. Insulated single stud stacks multiple ring-terminal conductors at one connection point. Includes insulator cap.
SKU BLUE-2002B
$10.80MSRP $12.96
Blue Sea SystemsBlue Sea Systems PowerPost Insulator
PowerPost Insulator, red, fits cable up to 2/0 AWG, 0.6in cable entry. The standard replacement cap for the entire single-stud PowerPost family.
SKU BLUE-4004
$3.50MSRP $4.20
Blue Sea SystemsBlue Sea Systems PowerPost Mini 1/4in-20 Stud
PowerPost connector, 1/4"-20 stud, 3/4" length (Mini), 48V DC maximum. Insulated single stud stacks multiple ring-terminal conductors at one connection point. Includes insulator cap.
SKU BLUE-2011B
$7.38MSRP $8.86
Blue Sea SystemsBlue Sea Systems PowerPost Mini 10-32 Stud
PowerPost connector, #10-32 stud, 5/8" length (Mini), 48V DC maximum. Insulated single stud stacks multiple ring-terminal conductors at one connection point. Includes insulator cap.
SKU BLUE-2010B
$7.17MSRP $8.60
Blue Sea SystemsBlue Sea Systems PowerPost Plus 3/8in-16 Stud
PowerPost connector, 3/8"-16 stud, 3/4" length (150A bus), 48V DC maximum. Insulated single stud stacks multiple ring-terminal conductors at one connection point. Includes insulator cap.
SKU BLUE-2103
$23.80MSRP $28.56
Blue Sea SystemsBlue Sea Systems Push Button Reset Only Circuit Breaker Boot - Black
Push Button Reset Only Circuit Breaker Boot - Black. Replaces standard mounting nut for mounting on Thermal Push Button Circuit Breakers only. UV resistant material resists discoloration and cracking.
SKU BLUE-137BLACK
$4.90MSRP $5.88
Blue Sea SystemsBlue Sea Systems Push Button Reset Only Circuit Breaker Boot - Clear
Push Button Reset Only Circuit Breaker Boot - Clear. Replaces standard mounting nut for mounting on Thermal Push Button Circuit Breakers only. UV resistant material resists discoloration and cracking.
SKU BLUE-135CLEAR
$4.90MSRP $5.88
Blue Sea SystemsBlue Sea Systems Push Button Reset Only Circuit Breaker Boot - White
Push Button Reset Only Circuit Breaker Boot - White. Replaces standard mounting nut for mounting on Thermal Push Button Circuit Breakers only. UV resistant material resists discoloration and cracking.
SKU BLUE-136WHITE
$4.90MSRP $5.88
Blue Sea SystemsBlue Sea Systems Push Button Switch Label Kit
Push Button Switch Label Kit. Scratch resistant polycarbonate material. Back printed for durability.
SKU BLUE-4230
$12.60MSRP $15.12
Blue Sea SystemsBlue Sea Systems Rotating Single Entry CableCap Small Pair
Rotating CableCap pair (black and red), for battery terminals with integral wing nut posts. Top rotates 360 degrees for cable entry from any angle.
SKU BLUE-4001
$7.00MSRP $8.40
Blue Sea SystemsBlue Sea Systems SI-ACR Automatic Charging Relay - 12/24V DC 120A
SI-ACR Automatic Charging Relay - 12/24V DC 120A. Protects sensitive electronics by temporary isolation of house loads from engine circuit during engine cranking. Designed for 12 or 24 volt systems.
SKU BLUE-7610
$124.60MSRP $149.52
Blue Sea SystemsBlue Sea Systems SPDT Remote Control Contura Switch - (ON)-OFF-(ON)
SPDT Remote Control Contura Switch - (ON)-OFF-(ON). Vibration, shock, thermoshock, moisture and salt spray resistant.
SKU BLUE-2145B
$25.90MSRP $31.08
Blue Sea SystemsBlue Sea Systems SPDT Remote Control Contura Switch, ON-OFF-ON
SPDT remote control Contura switch, ON-OFF-ON, red actuator, IP67 rated. Controls ML-Series remote battery switches and ML-ACR charging relays.
SKU BLUE-2146
$25.20MSRP $30.24
Blue Sea SystemsBlue Sea Systems ST Blade Fuse Block - 6 Independent Circuits with Cover
ST Blade Fuse Block - 6 Independent Circuits with Cover. Corrosion resistant, tin-plated copper fuse clips reduce heat and improve the efficiency of the electrical system. Clear insulating cover with label recesses accepts Small Format Labels.
SKU BLUE-5035
$36.40MSRP $43.68
Blue Sea SystemsBlue Sea Systems ST Blade Fuse Block 12 Circuits with Cover
12-circuit ST Blade fuse block with cover, 100A total / 30A per circuit, 32V DC max, no negative bus. Accepts ATO/ATC blade fuses, sold separately.
SKU BLUE-5029
$46.20MSRP $55.44
Blue Sea SystemsBlue Sea Systems ST Blade Fuse Block 12 Circuits with Negative Bus and Cover
12-circuit ST Blade fuse block, 100A total / 30A per circuit, 32V DC, with an integrated negative bus. Accepts ATO/ATC blade fuses, sold separately.
SKU BLUE-5026
$51.80MSRP $62.16
Blue Sea SystemsBlue Sea Systems ST Blade Fuse Block 6 Circuits with Cover
6-circuit ST Blade fuse block with cover, 100A total / 30A per circuit, 32V DC max, no negative bus. Accepts ATO/ATC blade fuses, sold separately.
SKU BLUE-5028
$36.40MSRP $43.68
Blue Sea SystemsBlue Sea Systems ST Blade Fuse Block 6 Circuits with Negative Bus and Cover
6-circuit ST Blade fuse block, 100A total / 30A per circuit, 32V DC, with an integrated negative bus. Accepts ATO/ATC blade fuses, sold separately.
SKU BLUE-5025
$42.00MSRP $50.40
Blue Sea SystemsBlue Sea Systems ST Blade Fuse Block 6 Independent Circuits
6 independent-circuit ST Blade fuse block, 30A per circuit / 40A per jumped group, 32V DC. Includes two terminal jumpers. Fuses sold separately.
SKU BLUE-5037
$41.30MSRP $49.56
Blue Sea SystemsBlue Sea Systems ST CLB Circuit Breaker Block - 6 Independent Circuits
ST CLB Circuit Breaker Block - 6 Independent Circuits. Quick connect clips allow circuit breakers to snap easily into place. Tin-plated copper busses and screw terminals.
SKU BLUE-5050
$51.80MSRP $62.16
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.