ark (Noah's ark)
Refers specifically to the biblical Noah's Ark. Often used in the phrase ノアの箱舟.
The story of Noah's Ark is in the Old Testament.
He made a model of the ark.
Noah's ark
Most common kanji form; used in news and general writing.
Ateji spelling; 方 is used phonetically. Rarely seen.
Alternate kanji form; 舟 emphasizes a small boat or vessel.
Compound of 箱 (hako, 'box') and 船 (fune, 'ship'), literally 'box ship'. The reading はこぶね is a rendaku form of はこ + ふね.