I think since it has one flat side, at first I thought was meant to sit against a wall, so it probably would not hold candles, due to fire danger.
Then I realized it may be only half of the object, and the other matching semicircle is missing. It looks like there might be some kind of drain plug on the bottom? In which case I would guess its a flower arranger with half missing and that candles go in the cups. A ship theme seems like a strange motif for a table centerpiece though. I could not find it on other Mann pieces. Hmmm... Interesting.