Blue Sea Systems ST-Blade Water-Resistant Fuse Block

The Blue Sea Systems ST-Blade Water-Resistant Fuse Block brings IP66-rated protection to the familiar ATO/ATC blade-fuse format, for locations exposed to spray or washdown where a standard open ST Blade block wouldn't hold up. It nests side-by-side with other water-resistant fuse blocks and Blue Sea's water-resistant 100A bus bars to build out a larger distribution point with minimal wiring.

Key features

• 4 circuits, 80A total, 25A per circuit, 32V DC maximum
• IP66 rated, CE marked
• Single-side nesting design allows wire entry from one side to maximize space
• Includes 3 wire plugs to maintain the water-resistant rating if fewer than 4 loads are used
• Accepts ATO/ATC fast-acting blade fuses and ATO/ATC-style low-profile circuit breakers

This is a newer addition to Blue Sea's ST Blade lineup (currently shown as "NEW" on the manufacturer's site), and a manual-cover variant is also available as PN 5056100 for installations that specifically need ABYC/USCG insulation-requirement documentation on the cover itself. Both share the same electrical ratings.

Because it accepts both fuses and low-profile circuit breakers in the same footprint, this block gives some flexibility to mix resettable and single-use protection across its 4 positions depending on what each circuit needs. It's a strong fit for helm, flybridge, or other exposed locations where circuit protection needs to survive routine spray without a separate enclosure. Because the input accepts up to 4 AWG wire while each load position steps down to 10 AWG, this block works well as a compact sub-distribution point fed by a single heavier supply cable, rather than requiring four separate heavy runs from the source.