The Abigail is a large luxury $10 Million dollar yacht, initially thought to belong to Strand. However, it seems more likely to belong to the Abigail family, in particular, Thomas Abigail, who is Strand's long term life partner. It is a location featured in Season 2 in Fear the Walking Dead.
This is one of the two places The Abigail can be controlled from, there are also controls in The Wheelhouse.
Two versions of this part of the set were built, the version seen here which is atop the main boat set and a upper-deck-controls-only set, pictured that leads to the main boat set by the jetty, built at ground level to make it easier to film.