There are many choices besides LEDs. Read the many threads on LEDs and decide if that's something you want.
Here's a list of the over 100 different bulbs that will physically fit where an 1141 is used:
SINGLE CONTACT (SC) BAYONET BASE (BA15S), BA15S, BA15s, BA15S BASE, BA15S BASE LIGHT BULB, BA15S BASE BULB, BA15S BASE LIGHT BULBS
Reasonable choices with slightly lower wattage would include:
#1003 MINIATURE BULB BA15S BASE - 12.8 Volt 0.94 Amp B6 SC Bayonet Base, 200 Hour
#1003LL LONG LIFE MINIATURE BULB BA15S BASE - 12.8 Volt .94 Amp B6 SC Bayonet Base, 400 Hour
#105 MINIATURE BULB BA15SS BASE - 12.8 Volt 1.0 Amp B6 Single Contact Base, 500 Hour
#93 MINIATURE BULB BA15S BASE - 12.8 Volt 1.04 Amp S8 Single Contact Bayonet Base, 700 Hour
#1139 MINIATURE BULB BA15S BASE - 12.8 Volt 1.04 Amp RP-11 SC Bayonet Base, 700 Hour
#77 MINIATURE BULB BA15S BASE - 13.0 Volt .37 Amp G5 S.C. Bayonet Base, 1,000 Hour
#89 MINIATURE BULB BA15S BASE - 13.0 Volt .58 Amp G6 Single Contact Base, 750 Hour
#89LL MINIATURE BULB LONG LIFE BA15S BASE - 13 Volt 0.58 Amp 7.54 Watt B-6, Single Contact (BA15S) Base, 1,500 Hour
#98 MINIATURE BULB BA15S BASE - 13.0 Volt 0.62 Amp G6 Single Contact Base, 800 Hour
#69 MINIATURE BULB BA15S BASE - 13.5 Volt 0.59 Amp G6 SC Bayonet Base, 5,000 Hour
#67 MINIATURE BULB BA15S BASE - 13.5 Volt .59 Amp G-6 SC Bayonet Base, 5,000 Hour
#1155 MINIATURE BULB BA15S BASE - 13.5 Volt .0.59 Amp G6 SC Bayonet Base, 5,000 Hour
#97 MINIATURE BULB BA15S BASE - 13.5 Volt .69 Amp G6 Single Contact Base, 5,000 Hour
#1247 MINIATURE BULB BA15S BASE - 14.0 Volt 0.43 Amp 6.02 Watt G-6 S.C. Bayonet Base, 1,000 Hour
#1095 MINIATURE BULB BA15S BASE - 14 Volt 0.51 Amp S8 Single Contact Bayonet Base, 5,000 Hour
#631 MINIATURE BULB BA15S BASE - 14.0 Volt 0.63 Amp G-6 SC Bayonet Base, 1,000 Hour
93 is probably the best choice because it has the same bulb shape and size, similar lifetime, and slightly lower light output and power draw. However the lifetime on shore power, where voltage will be closer to 13.5, will be low.
97 would be a good choice if you want a longer life bulb and can tolerate a little less light.
By way of reference, 1141 is a 12.8 volt, 1.44 amp, 1000 hour bulb with an s8 envelope.