Answer:

keel

Answer	Crossword Clue
KEEL	Tip (over)
KEEL	Topple (over)
KEEL	It's below belowdecks

KEEL	On an even ... (steady)
KEEL	Backbone of a boat
KEEL	Balance beam?
KEEL	Bottom of the sea?
KEEL	Place for barnacles
KEEL	Ocean bottom?
KEEL	Something a scow lacks
KEEL	What's even on a ship?

KEEL	What a ship's ribs are connected to
KEEL	Shipbuilder's starting point
KEEL	Beam from one end to the other
KEEL	Start for a shipbuilder
KEEL	Bow attachment
KEEL	Boat's backbone
KEEL	Bottom of the ocean?
KEEL	Nautical bottom

KEEL	F-G
KEEL	Fall (over)
KEEL	It should be even
KEEL	Nautical stabilizer
KEEL	Part of a hull
KEEL	It runs from stem to stern
KEEL	Ship part
KEEL	Frigate part

KEEL	Stem-to-stern item
KEEL	Ship's backbone
KEEL	It goes from stem to stern
KEEL	Hull part
KEEL	The constellation Carina
KEEL	Nautical centerpiece
KEEL	Hull projection
KEEL	Longitudinal boat timber

KEEL	Ship's spine
KEEL	Ship's central beam
KEEL	Boat's bottom
KEEL	Hull attachment