Looking for some low cost mini lights for you scale boat, Ray Agee found a great idea! The LEMAX Company manufactures a mini light string of 20 bulbs, which may be your answer. The mini light String requires two "AA" size 1.5V batteries (AC adaptor can be used for testing.)
The mini light string comes clear or in colors. These mini lights are used for miniature doll houses, to find them go to Ben Franklin Craft Store and ask for LEMAX Village Collection Mini Lights, item number 64128, price $5.00.