Description

The ACR C-Strobe H2O LED Water-Activated Strobe Light 3964.1 is a compact personal distress strobe designed for life jackets, inflatable PFDs, backpacks, ditch bags, and marine emergency kits. This H2O model can be activated manually with the ON/OFF button or automatically when armed and immersed in water. It features a bright 45 lumen white LED, three operating modes, and a waterproof impact-resistant housing for reliable emergency signaling.

Key Features

• ACR part number 3964.1 — C-Strobe H2O, carded version
• Water-activated personal distress strobe with manual ON/OFF operation
• Automatic activation when armed and immersed in water
• Three modes: strobe, steady-on, and SOS
• 45 lumen white LED
• Typical strobe operating life of 120+ hours
• Minimum strobe operating life of 100+ hours at -1°C
• Waterproof tested for 24 hours at 3.3 ft / 1 m
• Uses 2 AA batteries, sold separately
• Size: 5.56″ x 1.38″ x 1.2″ / 14.1 x 3.5 x 3.0 cm
• Weight: 1.4 oz / 40 g without batteries
• Reverse battery protection
• Carded version includes PFD clip, lanyard, and Velcro strap
• Certifications include USCG/SOLAS, CE, and Transport Canada

Intended Use

The C-Strobe H2O is intended for emergency visual distress signaling on life jackets, inflatable PFDs, vessel safety kits, ditch bags, backpacks, paddling gear, and personal survival equipment. Its water-activation feature makes it especially useful for PFD installations where the strobe may need to activate automatically after water entry.

Fitment Notice

This is the water-activated C-Strobe H2O 3964.1. For manual-only strobe use, the related C-Strobe model is 3965.1. Always confirm the required approval standard for your vessel, operating area, and onboard safety-equipment list before replacing or adding emergency signaling equipment.

When This Product Needs Replacement

Replace the strobe if the housing is cracked, the ON/OFF button becomes unreliable, the water-activation function fails testing, the battery compartment shows corrosion, the light output is weak, or the unit no longer meets required onboard safety standards. Batteries should be inspected regularly and replaced before expiry, seasonal launch, offshore trips, or long-term storage.

Installation Notes

Attach the C-Strobe H2O to a compatible life jacket, inflatable PFD, backpack strap, or emergency kit using the included mounting accessories. The flexible side lashing loops allow mounting to webbing or straps, while the included PFD clip is designed for attachment to an inflatable life jacket’s oral inflation tube. Install fresh AA batteries, verify the battery door is secure, and test both manual and water-activated operation before placing the strobe into service.

Alternate/Superseded Part Numbers

Related ACR C-Strobe references include:

• 3964.1 — C-Strobe H2O, carded water-activated version
• 3964 — C-Strobe H2O, bulk water-activated version
• 3965.1 — C-Strobe, carded manual version
• 3965 — C-Strobe, bulk manual version
• 3969 — C-Strobe H2O 10-pack reference

Parts Desk Insight

The main reason to choose 3964.1 is the combination of strobe output and automatic water activation. Compared with a steady emergency light, a flashing strobe is easier to pick out in poor visibility, and the water-activation feature is a strong match for life jacket and man-overboard setups.

Shipping:Ships within 3 days for fast Canada wide shipping.