Lunasea's navigation light bulbs are waterproof, have a lifetime warranty, and are rated for 2 nautical miles.
This LL28 series of bulb produce more intensity, drawing less power, and have a wider voltage input range than previous Lunasea bulbs.

Designed for 2 nautical mile, Series 40 type navigation lights, like Aqua Signal's port, starboard, stern and all-round fixtures. These double contact bayonet bulbs have indexed base pins (one higher, one lower) so they only mount into the nav fixture in the correct oriientation.
Not easily seen in the photos, these bulbs have three illuminating faces producing 360 of light.

Bulb base BAY-15d, indexed double contact bayonet
EMI and surge protected
Encapsulated to protect from the elements
Maintains full brightness from 10 to 45V DC
Small design - only 48.5 mm tall and 30 mm wide

Note - Only use the corresponding colored LED bulb in (port/starboard) fixtures with colored lenses.