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 ANL Fuse Block with Insulating Cover - 35 to 750A
ANL Fuse Block with Insulating Cover - 35 to 750A. Cover included. Accepts 5/16" (M8) ring terminals.
SKU BLUE-5503
$48.30MSRP $57.96
Blue Sea SystemsBlue Sea Systems BatteryLink Automatic Charging Relay 12/24V DC 120A
BatteryLink ACR, 120A continuous, 12/24V DC auto-ranging, IP67. Automatically combines and isolates two battery banks based on charge state.
SKU BLUE-7611
$102.20MSRP $122.64
Blue Sea SystemsBlue Sea Systems CableCap Black 0.47 to 0.13 Stud
Black PVC CableCap, insulates a single stud connector. Fits cable sizes 10, 12, 14, 16, 18 AWG. For alternators, starters, windlasses, and similar high-amperage devices.
SKU BLUE-4009
$3.50MSRP $4.20
Blue Sea SystemsBlue Sea Systems CableCap Black 0.50 Stud
Black PVC CableCap, insulates a single stud connector. Fits cable sizes 1, 2, 1/0, 2/0 AWG. For alternators, starters, windlasses, and similar high-amperage devices.
SKU BLUE-4013B
$2.15MSRP $2.58
Blue Sea SystemsBlue Sea Systems CableCap Black 0.70 to 0.30 Stud
Black PVC CableCap, insulates a single stud connector. Fits cable sizes 4, 6, 8 AWG. For alternators, starters, windlasses, and similar high-amperage devices.
SKU BLUE-4011
$3.50MSRP $4.20
Blue Sea SystemsBlue Sea Systems CableCap Red 0.47 to 0.13 Stud
Red PVC CableCap, insulates a single stud connector. Fits cable sizes 10, 12, 14, 16, 18 AWG. For alternators, starters, windlasses, and similar high-amperage devices.
SKU BLUE-4008
$3.50MSRP $4.20
Blue Sea SystemsBlue Sea Systems CableClam with Stainless Steel Dress Cap 1.40in
CableClam bulkhead cable entry, stainless steel dress cap, fits cable up to 0.56in dia. with connectors up to 1.40in. Watertight pass-through.
SKU BLUE-1003100
$35.70MSRP $42.84
Blue Sea SystemsBlue Sea Systems Class T Fuse - 400 Amp
Class T Fuse - 400 Amp. Extremely fast short-circuit response. 20,000 Ampere Interrupt Capacity (AIC).
SKU BLUE-5121
$74.20MSRP $89.04
Blue Sea SystemsBlue Sea Systems Class T Fuse 125A 125V DC
125A Class T fuse, 125V DC max, with a 20,000A interrupt rating for inverter and large lithium battery bank protection. Use with a Class T Fuse Block, sold separately.
SKU BLUE-5113
$58.10MSRP $69.72
Blue Sea SystemsBlue Sea Systems Class T Fuse 250A 125V DC
250A Class T fuse, 125V DC max, with a 20,000A interrupt rating for inverter and large lithium battery bank protection. Use with a Class T Fuse Block, sold separately.
SKU BLUE-5118
$74.20MSRP $89.04
Blue Sea SystemsBlue Sea Systems Class T Fuse 300A 125V DC
300A Class T fuse, 125V DC max, with a 20,000A interrupt rating for inverter and large lithium battery bank protection. Use with a Class T Fuse Block, sold separately.
SKU BLUE-5119
$74.20MSRP $89.04
Blue Sea SystemsBlue Sea Systems Class T Fuse 350A 125V DC
350A Class T fuse, 125V DC max, with a 20,000A interrupt rating for inverter and large lithium battery bank protection. Use with a Class T Fuse Block, sold separately.
SKU BLUE-5120
$74.20MSRP $89.04
Blue Sea SystemsBlue Sea Systems Class T Fuse Block 225-400A
Class T fuse block with clear insulating cover, 400A / 160V DC max, 4/0 AWG cable capacity. Not ignition protected. Class T fuse sold separately.
SKU BLUE-5502
$48.30MSRP $57.96
Blue Sea SystemsBlue Sea Systems Class T Fuse Block Ignition Protected 110-200A
Ignition-protected Class T fuse block for 110-200A Class T fuses, 160V DC max, 4/0 AWG cable capacity. SAE J1171 / ISO 8846. Fuse sold separately.
SKU BLUE-5007100
$70.00MSRP $84.00
Blue Sea SystemsBlue Sea Systems Common 100A Mini BusBar 4 Gang
100A mini busbar, four #10-32 stud terminals, no screw terminals included. Rated 300V AC / 48V DC maximum. Great for limited space applications.
SKU BLUE-2305
$17.50MSRP $21.00
Blue Sea SystemsBlue Sea Systems Common 100A Mini BusBar 5 Gang
100A mini busbar, 5 screw terminals plus 2 stud terminals in a compact body. Rated 300V AC / 48V DC maximum for limited-space installations.
SKU BLUE-2304B
$9.75MSRP $11.70
Blue Sea SystemsBlue Sea Systems Common 150A BusBar 20 Gang with Cover
150A common busbar, 20 screw terminals plus 2 stud terminals, with a clear polycarbonate cover included for insulated terminals. Rated 300V AC / 48V DC maximum.
SKU BLUE-2312
$39.20MSRP $47.04
Blue Sea SystemsBlue Sea Systems Common 150A BusBar Four 1/4in-20 Studs
150A common busbar, four 1/4in stud terminals, no screw terminals included on this version. Rated 300V AC / 48V DC maximum. For ring-terminal wiring only, no cover.
SKU BLUE-2303
$28.00MSRP $33.60
Blue Sea SystemsBlue Sea Systems Common BusBar Cover for PN 2301 and PN 2303
Clear insulating busbar cover, fits Common 150A BusBar PN 2301 (10-gang) and PN 2303 (4-stud). Snaps on with no tools to satisfy ABYC/USCG insulation requirements.
SKU BLUE-2715
$4.20MSRP $5.04
Blue Sea SystemsBlue Sea Systems DC Analog Ammeter - 0 to 150A with Shunt
DC Analog Ammeter - 0 to 150A with Shunt. Simple 4-wire connection from shunt. Meter senses and powers from shunt connection.
SKU BLUE-8018
$80.50MSRP $96.60
Blue Sea SystemsBlue Sea Systems DC Analog Ammeter 0-100A with Shunt
DC analog ammeter, 0-100A display range, includes an external DC shunt. Simple 4-wire connection, backlit face with separate 12V/24V backlight leads.
SKU BLUE-8017
$80.50MSRP $96.60
Blue Sea SystemsBlue Sea Systems DC Analog Voltmeter 8-16V
DC analog voltmeter, 8-16V display range, simple 2-wire connection, backlit face. Meter current 1mA at full scale, accuracy 2.5% of scale range.
SKU BLUE-8003
$39.90MSRP $47.88
Blue Sea SystemsBlue Sea Systems DC Digital Ammeter -500 to 500A
DC digital ammeter, -500A to +500A display range, includes a 500A shunt. Surface mounts in a 2in round hole. Applicable for 12-42V DC systems.
SKU BLUE-8236
$217.70MSRP $261.24
Blue Sea SystemsBlue Sea Systems DC Digital Multi-Function Meter with Alarm
DC digital multi-function meter, displays -500A to +500A current and 0-60V voltage. High/low voltage audio and visual alarms, standard 2in mount.
SKU BLUE-8248
$280.70MSRP $336.84
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.