create 'cm' object
read.oce(file = "/data/archive/sleiwex/2008/moorings/m11/cm/interocean_0811786/manufacturer/cm_interocean_0811786.s4a.tab",     from = 840, to = 840 + 24 * 60)
subset.cm(x, subset=time < as.POSIXct("2008-06-27 00:00:00", tz = "UTC"))