A lot depends on what you mean by oceanworthy. If you are looking for a boat that a majority of the people who post here would take offshore - I don't think that there really is one that is trailerable. Any boat can be put on a trailer and towed if you have a big enough truck, but the one characteristic that boats generally considered to be offshore cruisers all share, is a substantial displacement - i.e.: they weigh a lot more than the average trailer sailer. It is darn near impossible to launch them from a trailer short of backing the trailer over a cliff and hoping the boat lands keel down.
That said, a lot of voyages have been made in boats that were not designed for extended cruising... 24 foot Sharks have cruised from Canada to the Bahamas, over to Europe, and back. Some West Wight Potters have made open water trips, and I am sure that if you research you'll find many other examples.
If, for some reason, I HAD to go offshore in a boat that could be trailered and lauched on a ramp then I'd probably start by looking for a Bayfield 25 or Balboa 26, perhaps a Nordica 20... But it would not be something I'd do of my own volition. But then again, I am older and wiser now than I should be I guess...