From A Wiki of Ice and Fire
Summer's Dream is a carrack.
A Clash of Kings
The Summer's Dream was hired by Tyrion Lannister while he was in King's Landing. It took Janos Slynt and six others to the Wall via Gulltown, the Three Sisters, Skagos and then Eastwatch-by-the-sea. The master of the ship was told to throw Allar Deem over the side when they got out to sea.
- ↑ 1.0 1.1 A Clash of Kings, Chapter 8, Tyrion II.