The brochure is available online at Marlow-Hunter and states the 340 is rated to CE classification A which would be required to reach most of the European market.

http://www.marlow-hunter.com/Models2011/HunterPreviousModels/H340Brochure2001.pdf

The rating has some good value in the initial design of the boat but doesn't give any indication how the boat will hold up over time or how well it handles heavy weather and long distance voyaging. Hunter boats are generally intended for sheltered water and are very well designed for this purpose. They have nicely appointed accommodations and plenty of space down below. Systems are well put together and decent quality. Thanks to the volume of boats that Hunter produced they were able to put quite a bit of effort into engineering and amortize the costs over a large production run. There was however a big focus on cost in order to keep the price down and reach a broader market.

All boats are a comprise and Hunter focused on the largest portion of the market which is coastal and inland sailing. Boats such as Valiant, Pacific Seacraft or Caliber tended to go after the smaller offshore and long term cruiser market and so are more appropriate for long distance cruising. The Hunter may be able to cross an ocean but it is not going to be the most comfortable boat to do so on.