The US Coast Guard has suspended its air search for a missing Bermuda sailboat after a second unsuccessful day.Two Bermudians are aboard the 34-foot sailboat Carefree IV and have not been seen since December 18. The sailors have not been named.Today a Bermuda Maritime Operations official said the Coast Guard C-130 aircraft spent the morning flying over the area where the boat was last seen approximately 210 nautical miles South Southwest of Bermuda.It was the second day the aircraft was deployed to search for the sailors, but the official said they have now suspended their aircraft searches.Said a spokesman: "RCC Bermuda has been in contact with authorities in the Dominican Republic who are carrying out port checks to see if the vessel may have returned south and continue with urgent marine information broadcasts to vessels transiting the area South and East of Bermuda."The search by air has been suspended pending new information while merchant vessels transiting the area continue to keep a sharp lookout."The sailors left the Dominican Republic on December 1 and were expected to arrive in Bermuda earlier this week.Because of the recent bad weather, Bermuda Maritime Operations began issuing advisories to ships in the area yesterday, to report any sightings. They will continue to issue advisories asking merchant ships in the area to be on the look out for the sailors.