Hornbeck Offshore Services Inc., Covington, La., (NYSE: HOS) has closed its acquisition of 20 offshore supply vessels (OSVs) and related business from certain affiliates of Nabors Industries Ltd., Houston, (NYSE: NBR) for $186 million in cash. The Sea Mar fleet is comprised of 10 200-class DP-1 new-generation OSVs and 10 conventional OSVs. Hornbeck also acquired one 285-foot DP-2 new-generation OSV currently under construction at a domestic shipyard with an anticipated fourth-quarter 2008 delivery. The total estimated cost of this newbuild vessel is approximately $34 million, of which $7.3 million was paid to Nabors at closing.