The boom in U.S. onshore oil and natural gas drilling has yet to peak, bolstering forecasts of continued strong demand for rigs, analysts and executives said this week. But growth in the onshore rig market is likely to slow down next year, and activity in the offshore market is already tailing off, with some companies sending rigs away from the Gulf of Mexico to other countries where profits may be better. "We expect to see 30 to 33 percent growth in the total U.S. rig count this year over 2000," an analyst said. "The problem is, we'll only see 8 percent growth from 2001 to 2002, and then companies will have to add units," the analyst added, noting that the 2001 rig count increased 49 percent from 1999 to 2001.