The following is the format (fortran) information for
NODC file header and data records located in the ftp site.
CTD casts are appended together for an entire cruise.

i = integer, a=character, t=field begins at that column number

header (t80 = 1):
t1, i2 = country code (31 = U.S.)
t3, A2 = ship code (a4 = albatross iv, 6g = deleware, kt = katahdin...etc)
t5, i5 = latitude  example: 40302 is 40 deg, 30.2 minutes
t10, i6 = longitude (same format as latitude)
t17, i4 = year
t21, i2 = month
t23, i2 = day
t25, i4 = GMT time  example 1150 is 11.50 or 11:30
t29, i2 = cruise code
t31, i3 = cast number
t34, i4 = station bottom depth
t39, a1 = deployment method (V=vertical profile, B=bongo, W=water cast)
t42, i4 = CTD serial number used for that particular cast
t70, i3 = station number
t80, i1 = flag (1 = header record)

data records (t80 = 3):
t28, i4 = pressure (db)
t33, i4 = temperature (1138 = 11.38 deg. C)
t38, i5 = salinity (32528 = 32.528 psu)
t43, i4 = density (sigma-t, 2241 = 22.41)
t60, i4 = fluorescence in volts if CTD equipped with a fluorometer, 1432 = 1.432 volts)
t80, i1 = flag (3 = data record)