Question: In Irish mythology, Niamh is the daughter of Manannán mac Lir, a sea deity in Irish mythology, and he is said to own a boat named what?

Context paragraphs:
Fragarach: In Irish mythology, Fragarach (or "Freagarthach"), known as 'The Answerer' or 'The Retaliator', was the sword of Manannan mac Lir and later, Lugh Lamfada.

Niamh (mythology): In Irish mythology, Niamh is the daughter of Manannán mac Lir.  She is one of the Queens of Tir na nÓg, and might also be the daughter of Fand.

Fionnuala: In Irish mythology, Finnguala (modern spellings: Fionnghuala or Fionnuala; literally "fionn-ghuala" meaning "fair-shoulder") was the daughter of Lir of the Tuatha Dé Danann.  In the legend of the Children of Lir, she was changed into a swan and cursed by her stepmother, Aoife, to wander the lakes and rivers of Ireland, with her brothers Fiachra, Conn and Aodh, for 900 years until saved by the marriage of Lairgren, son of Colman, son of Cobthach, and Deoch, daughter of Finghin, whose union broke the curse.  'The Song of Albion', with lyrics by Thomas Moore speaks of her wanderings.

Mongán mac Fiachnai: Mongán mac Fiachnai (died "ca."  625) was an Irish prince of the Cruthin, a son of Fiachnae mac Báetáin.  Little is certainly known of Mongán's life as only his death is recorded in the Irish annals.  He appears as a character in the Cycles of the Kings where he is said to have been the son of Manannán mac Lir and perhaps a reincarnation of the legendary hero Finn mac Cumaill of the Fenian Cycle.

His Three Calls to Cormac: His Three Calls to Cormac, or ""Cormac's Adventure in the Land of Promise"", is a tale found in Irish mythology; the title being from "Gods and Fighting Men – The Story of the Tuatha De Danaan and of the Fianna of Ireland", which is a collection of tales collated and translated by Lady Augusta Gregory.  This particular tale features the Irish sea deity Manannán mac Lir and High King Cormac mac Airt.

Emain Ablach: Emain Ablach (also Emne; Middle Irish Emhain Abhlach or Eamhna; meaning "Emhain of the Apples") is a mythical island paradise in Irish mythology.  It is often regarded as the realm of the sea god Manannán Mac Lir and identified with either the Isle of Man or the Isle of Arran.  According to the medieval Irish poem Baile Suthain Sith Eamhna, the god Lug Lamfada was reared in Emain Ablach.

Manawydan: Manawydan fab Llŷr is a figure of Welsh mythology, the son of Llŷr and the brother of Brân the Blessed and Brânwen.  The first element in his name is cognate with the stem of the name of the Irish sea god Manannán mac Lir, and likely originated from the same Celtic deity as Manannán.  Unlike Manannán, however, no surviving material connects him with the sea in any way except for his patronymic ("llŷr" is an old Welsh word for "sea").  Manawydan's most important appearances occur in the Second and Third Branches of the Mabinogi (the later of which is named for him), but he is also referenced frequently in medieval poetry and the Welsh Triads.

Manannán mac Lir: Manannán or Manann, also known as Manannán mac Lir ("Mac Lir" meaning "son of the sea"), is a sea deity in Irish mythology.  He is affiliated with both the Tuatha Dé Danann and the Fomorians.  In the tales, he is said to own a boat named "Scuabtuinne" ("Wave Sweeper"), a sea-borne chariot drawn by the horse "Enbarr", a powerful sword named "Fragarach" ("The Answerer"), and a cloak of invisibility ("féth fíada").  He is seen as the guardian of the Otherworld and one who ferries souls to the afterlife.  Manannán is furthermore identified with the trickster figure "Bodach an Chóta Lachtna" ("the churl in the drab coat").

Ler (mythology): Ler (meaning "Sea" in Old Irish; "Lir" is the genitive form) is a sea god in Irish mythology.  His name suggests that he is a personification of the sea, rather than a distinct deity.  He is named "Allód" in early genealogies, and corresponds to the Llŷr of Welsh mythology.  Ler is chiefly an ancestor figure, and is the father of the god Manannán mac Lir, who appears frequently in medieval Irish literature.  Ler appears as the titular king in the tale "The Children of Lir".

Llŷr: Llŷr (Welsh: "Llŷr Llediaith" (] ); "Lleddiaith" meaning "half-speech" or "half-language") is a figure in Welsh mythology, probably originally a deity, probably derived from Irish Ler ("the Sea"), father of "Manannán mac Lir".

Supporting paragraphs: Niamh (mythology) Manannán mac Lir
Answer: Scuabtuinne