I popped a Terralux TLE-1F bulb into a 6V 'floating lantern'. 50 lumens.
Out throws my '900 lumen' MTE SSC-P7.
Never found out if it floats.
Donut hole at less than 2 meters/7 feet. OK beyond that.
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I have tried the TLE-1F in an earlier version of one of these: 4AA 1 LED floating lantern/cool blue etc. (back in 2000 they were 3 lumen, not the current 25.)
http://dorcy.com/products.aspx?p=412498
Donut hole at all distances.
Ended up using a Tektite LPR-3™ bulb 4.5V with 4 NiMH 4.8V.
(The 4 cell LPR-113 was quite dim on 4 NiMH, maybe only as bright as the current stock bulb.)