diff --git a/qctests/CSIRO_gradient.py b/qctests/CSIRO_constant_bottom.py
similarity index 50%
rename from qctests/CSIRO_gradient.py
rename to qctests/CSIRO_constant_bottom.py
index a9606c8..64539eb 100644
--- a/qctests/CSIRO_gradient.py
+++ b/qctests/CSIRO_constant_bottom.py
@@ -1,6 +1,6 @@
 """
-Implements the gradient test of DOI: 10.1175/JTECHO539.1
-All questionable features result in a flag, in order to minimize false negatives
+Implements CSIRO's constant-bottom check
+All questionable features result in a flag, in order to minimize false negatives 
 """
 
 import numpy
@@ -14,15 +14,13 @@ def test(p):
 
     # Get temperature values from the profile.
     t = p.t()
-    # Get depth values (m) from the profile.
+    # depths
     d = p.z()
     # is this an xbt?
     isXBT = p.probe_type() == 2
-
-    assert len(t.data) == len(d.data), 'Number of temperature measurements does not equal number of depth measurements.'
+    latitude = p.latitude()
 
     # initialize qc as a bunch of falses;
-    # implies all measurements pass when a gradient can't be calculated, such as at edges & gaps in data:
     qc = numpy.zeros(len(t.data), dtype=bool)
 
     # check for gaps in data
@@ -30,13 +28,9 @@ def test(p):
     isDepth = (d.mask==False)
     isData = isTemperature & isDepth
 
-    for i in range(0,len(t.data)-1):
-        if isData[i] & isData[i+1]:
-
-            gradient = (d.data[i+1] - d.data[i]) / (t.data[i+1] - t.data[i]) 
-            
-            # gradient flag
-            if gradient > -0.4 and gradient < 12.5:
-                qc[i] = True
+    # constant temperature at bottom of profile, for latitude > -40 and bottom two depths at least 30m apart:
+    if isData[-1] and isData[-2] and isXBT:
+        if t.data[-1] == t.data[-2] and latitude > -40 and d.data[-1] - d.data[-2] > 30:
+            qc[-1] = True
 
-    return qc
+    return qc
\ No newline at end of file
diff --git a/qctests/CSIRO_long_gradient.py b/qctests/CSIRO_long_gradient.py
new file mode 100644
index 0000000..ad3308d
--- /dev/null
+++ b/qctests/CSIRO_long_gradient.py
@@ -0,0 +1,52 @@
+"""
+Implements CSIRO's long gradient check
+All questionable features result in a flag, in order to minimize false negatives 
+"""
+
+import numpy
+
+def test(p):
+    """
+    Runs the quality control check on profile p and returns a numpy array
+    of quality control decisions with False where the data value has
+    passed the check and True where it failed.
+    """
+
+    # depths
+    d = p.z()
+    # temperatures
+    t = p.t()
+
+    # initialize qc as a bunch of falses;
+    qc = numpy.zeros(len(t.data), dtype=bool)
+
+    # check for gaps in data
+    isDepth = (d.mask==False)
+    isTemperature = (t.mask==False)
+    isData = isTemperature & isDepth
+
+    on_inv = False # are we currently in an inversion?
+
+    for i in range(0, p.n_levels()-1 ):
+        if isData[i] and isData[i+1]:
+            # not interested below 5m:
+            if d.data[i] < 5: continue
+
+            if t.data[i+1] > t.data[i] and not on_inv:
+                # entering an inversion
+                start_inv_temp = t.data[i]
+                start_inv_depth = d.data[i]
+                potential_flag = i
+                on_inv = True
+
+            if t.data[i+1] < t.data[i] and on_inv:
+                # exiting the inversion
+                end_inv_temp = t.data[i]
+                end_inv_depth = d.data[i]
+                on_inv = False
+                gradlong = (end_inv_depth - start_inv_depth) / (end_inv_temp - start_inv_depth)
+
+                if abs(gradlong) < 4:
+                    qc[potential_flag] = True
+
+    return qc
\ No newline at end of file
diff --git a/qctests/CSIRO_short_gradient.py b/qctests/CSIRO_short_gradient.py
new file mode 100644
index 0000000..959756a
--- /dev/null
+++ b/qctests/CSIRO_short_gradient.py
@@ -0,0 +1,37 @@
+"""
+Implements CSIRO's short gradient check
+All questionable features result in a flag, in order to minimize false negatives 
+"""
+
+import numpy
+
+def test(p):
+    """
+    Runs the quality control check on profile p and returns a numpy array
+    of quality control decisions with False where the data value has
+    passed the check and True where it failed.
+    """
+
+    # depths
+    d = p.z()
+    # temperatures
+    t = p.t()
+
+    # initialize qc as a bunch of falses;
+    qc = numpy.zeros(len(t.data), dtype=bool)
+
+    # check for gaps in data
+    isDepth = (d.mask==False)
+    isTemperature = (t.mask==False)
+    isData = isTemperature & isDepth
+
+    for i in range(0, p.n_levels()-1 ):
+        if isData[i] and isData[i+1]:
+            deltaD = (d.data[i+1] - d.data[i]) 
+            deltaT = (t.data[i+1] - t.data[i])
+            gradshort = deltaD / deltaT 
+            if (deltaT > 0.5 and deltaD < 30) or abs(gradshort) < 0.4 or (gradshort > 0 and gradshort < 12.5):
+                if abs(deltaT) > 0.4:
+                    qc[i] = True
+
+    return qc
\ No newline at end of file
diff --git a/qctests/CSIRO_surface_spikes.py b/qctests/CSIRO_surface_spikes.py
new file mode 100644
index 0000000..f88c601
--- /dev/null
+++ b/qctests/CSIRO_surface_spikes.py
@@ -0,0 +1,38 @@
+"""
+Implements CSIRO's surface spike check
+All questionable features result in a flag, in order to minimize false negatives 
+"""
+
+import numpy
+
+def test(p):
+    """
+    Runs the quality control check on profile p and returns a numpy array
+    of quality control decisions with False where the data value has
+    passed the check and True where it failed.
+    """
+
+    # depths
+    d = p.z()
+    # is this an xbt?
+    isXBT = p.probe_type() == 2
+
+    # initialize qc as a bunch of falses;
+    qc = numpy.zeros(len(d.data), dtype=bool)
+
+    # check for gaps in data
+    isDepth = (d.mask==False)
+
+    if not isXBT:
+        return qc
+
+    # flag any level that is shallower than 4m and is followed by a level shallower than 8m.
+    for i in range(p.n_levels()):
+        if isDepth[i]:
+            if d.data[i] < 4 and i < p.n_levels()-1: #only interested in depths less than 4m and not at the bottom of the profile.
+                if d.data[i+1] < 8:
+                    qc[i] = True
+            else:
+                break
+
+    return qc
\ No newline at end of file
diff --git a/qctests/CSIRO_wire_break.py b/qctests/CSIRO_wire_break.py
index 0191d15..68fc2e7 100644
--- a/qctests/CSIRO_wire_break.py
+++ b/qctests/CSIRO_wire_break.py
@@ -24,9 +24,8 @@ def test(p):
     isTemperature = (t.mask==False)
 
     # wire breaks at bottom of profile:
-    i = len(t.data)-1
-    if isTemperature[i] and isXBT:
-        if t.data[i] < -2.8 or t.data[i] > 36:
-            qc[i] = True
+    if isTemperature[-1] and isXBT:
+        if t.data[-1] < -2.8 or t.data[-1] > 36:
+            qc[-1] = True
 
     return qc
\ No newline at end of file
diff --git a/tests/CSIRO_constant_bottom_validation.py b/tests/CSIRO_constant_bottom_validation.py
new file mode 100644
index 0000000..e142ec5
--- /dev/null
+++ b/tests/CSIRO_constant_bottom_validation.py
@@ -0,0 +1,43 @@
+import qctests.CSIRO_constant_bottom
+import util.testingProfile
+import numpy
+
+##### CSIRO_constant_bottom ---------------------------------------------------
+
+def test_CSIRO_constant_bottom():
+    '''
+    Spot-check the nominal behavior of the CSIRO constant bottom test.
+    '''
+
+    # nominal
+    p = util.testingProfile.fakeProfile([0,0,0], [0,100,200], latitude=0, longitude=0, probe_type=2) 
+    qc = qctests.CSIRO_constant_bottom.test(p)
+    truth = numpy.zeros(3, dtype=bool)
+    truth[2] = True
+
+    assert numpy.array_equal(qc, truth), 'failed to flag a constant temperature at bottom of profile' 
+
+    # inappropriate probe type
+    p = util.testingProfile.fakeProfile([0,0,0], [0,100,200], latitude=0, longitude=0, probe_type=1) 
+    qc = qctests.CSIRO_constant_bottom.test(p)
+    truth = numpy.zeros(3, dtype=bool)
+
+    assert numpy.array_equal(qc, truth), 'flagged a constant temperature for an inappropriate probe type' 
+
+    # inappropriate latitude
+    p = util.testingProfile.fakeProfile([0,0,0], [0,100,200], latitude=-41, longitude=0, probe_type=2) 
+    qc = qctests.CSIRO_constant_bottom.test(p)
+
+    assert numpy.array_equal(qc, truth), 'flagged a constant temperature for an inappropriate latitude' 
+
+    # inappropriate depth difference
+    p = util.testingProfile.fakeProfile([0,0,0], [0,100,100], latitude=0, longitude=0, probe_type=2) 
+    qc = qctests.CSIRO_constant_bottom.test(p)
+
+    assert numpy.array_equal(qc, truth), 'flagged a constant temperature for an inappropriate depth distance'
+
+    # not at bottom of profile
+    p = util.testingProfile.fakeProfile([0,0, -1], [100,200,300], latitude=0, longitude=0, probe_type=2) 
+    qc = qctests.CSIRO_constant_bottom.test(p)
+
+    assert numpy.array_equal(qc, truth), 'flagged a constant temperature not at the bottom of the profile'
\ No newline at end of file
diff --git a/tests/CSIRO_gradient_validation.py b/tests/CSIRO_gradient_validation.py
deleted file mode 100644
index 34090d5..0000000
--- a/tests/CSIRO_gradient_validation.py
+++ /dev/null
@@ -1,22 +0,0 @@
-import qctests.CSIRO_gradient
-import util.testingProfile
-import numpy
-
-##### CSIRO_gradient_test ---------------------------------------------------
-
-def test_CSIRO_gradient():
-    '''
-    Spot-check some values in the CSIRO gradient test.
-    '''
-
-    p = util.testingProfile.fakeProfile([0,10,0,0.1,-24.9,-24.1], [10,20,30,40,50,60]) 
-    qc = qctests.CSIRO_gradient.test(p)
-    truth = numpy.zeros(6, dtype=bool)
-    truth[0] = True;  # in range
-    truth[1] = False; # too low
-    truth[2] = False; # too high
-    truth[3] = False; # right on the low margin
-    truth[4] = False; # right on the high margin
-    truth[5] = False; # can't caluclate gradient at endpoint
-
-    assert numpy.array_equal(qc, truth), 'nominal beahvior failure in CSIRO_gradient'
\ No newline at end of file
diff --git a/tests/CSIRO_long_gradient_validation.py b/tests/CSIRO_long_gradient_validation.py
new file mode 100644
index 0000000..6e69f68
--- /dev/null
+++ b/tests/CSIRO_long_gradient_validation.py
@@ -0,0 +1,34 @@
+import qctests.CSIRO_long_gradient
+import util.testingProfile
+import numpy
+
+##### CSIRO_long_gradient ---------------------------------------------------
+
+def test_CSIRO_long_gradient():
+    '''
+    Spot-check the nominal behavior of the CSIRO long gradient test.
+    '''
+
+    # nominal
+    p = util.testingProfile.fakeProfile([20,10,15,15,15,10], [0,5,10,15,20,25]) 
+    qc = qctests.CSIRO_long_gradient.test(p)
+    truth = numpy.zeros(6, dtype=bool)
+    truth[1] = True
+
+    assert numpy.array_equal(qc, truth), 'failed to flag a nominal long inversion'
+
+    # gradlong too large
+    p = util.testingProfile.fakeProfile([20,10,15,15,15,10], [0,10,20,30,40,50]) 
+    qc = qctests.CSIRO_long_gradient.test(p)
+    truth = numpy.zeros(6, dtype=bool)
+
+    assert numpy.array_equal(qc, truth), 'should not flag a long inversion with such a large gradient'   
+
+    # too shallow
+    p = util.testingProfile.fakeProfile([20,10,15,15,15,10], [0,1,6,11,16,21]) 
+    qc = qctests.CSIRO_long_gradient.test(p)
+    truth = numpy.zeros(6, dtype=bool)
+
+    print truth, qc
+
+    assert numpy.array_equal(qc, truth), 'should not flag a long inversion that begins at < 5m' 
\ No newline at end of file
diff --git a/tests/CSIRO_short_gradient_validation.py b/tests/CSIRO_short_gradient_validation.py
new file mode 100644
index 0000000..9f6563c
--- /dev/null
+++ b/tests/CSIRO_short_gradient_validation.py
@@ -0,0 +1,30 @@
+import qctests.CSIRO_short_gradient
+import util.testingProfile
+import numpy
+
+##### CSIRO_short_gradient ---------------------------------------------------
+
+def test_CSIRO_short_gradient():
+    '''
+    Spot-check the nominal behavior of the CSIRO short gradient test.
+    '''
+
+    # nominal
+    p = util.testingProfile.fakeProfile([0,1], [0,10]) 
+    qc = qctests.CSIRO_short_gradient.test(p)
+    truth = numpy.zeros(2, dtype=bool)
+    truth[0] = True
+
+    assert numpy.array_equal(qc, truth), 'failed to flag a gradient at small delta-temp and delta-depth'
+
+    p = util.testingProfile.fakeProfile([0,10], [0,100]) 
+    qc = qctests.CSIRO_short_gradient.test(p)
+
+    assert numpy.array_equal(qc, truth), 'failed to flag a gradient outside of delta temp and depth ranges, but inside gradshort ranges'     
+
+    # temperature change too small
+    p = util.testingProfile.fakeProfile([0,0.1], [0,0.2]) 
+    qc = qctests.CSIRO_short_gradient.test(p)
+    truth = numpy.zeros(2, dtype=bool)
+
+    assert numpy.array_equal(qc, truth), 'flagged a gradient even though its temperature change was too small to consider' 
\ No newline at end of file
diff --git a/tests/CSIRO_surface_spikes.py b/tests/CSIRO_surface_spikes.py
new file mode 100644
index 0000000..03c4250
--- /dev/null
+++ b/tests/CSIRO_surface_spikes.py
@@ -0,0 +1,33 @@
+import qctests.CSIRO_surface_spikes
+import util.testingProfile
+import numpy
+
+##### CSIRO_surface_spikes ---------------------------------------------------
+
+def test_CSIRO_surface_spikes():
+    '''
+    Spot-check the nominal behavior of the CSIRO CSIRO_surface_spikes test.
+    '''
+
+    # nominal
+    p = util.testingProfile.fakeProfile([0,0,0], [1,2,3], probe_type=2) 
+    qc = qctests.CSIRO_surface_spikes.test(p)
+    truth = numpy.zeros(3, dtype=bool)
+    truth[0] = True
+    truth[1] = True
+
+    assert numpy.array_equal(qc, truth), 'failed to flag a collection of shallow profiles' 
+
+    # inappropriate probe type
+    p = util.testingProfile.fakeProfile([0,0,0], [1,2,3], probe_type=1) 
+    qc = qctests.CSIRO_surface_spikes.test(p)
+    truth = numpy.zeros(3, dtype=bool)
+
+    assert numpy.array_equal(qc, truth), 'flagged shallow profiles for an inappropriate probe type' 
+
+    # no cluster
+    p = util.testingProfile.fakeProfile([0,0,0], [1,20,30], probe_type=1) 
+    qc = qctests.CSIRO_surface_spikes.test(p)
+    truth = numpy.zeros(3, dtype=bool)
+
+    assert numpy.array_equal(qc, truth), 'flagged shallow profile without a cluster' 
\ No newline at end of file
diff --git a/util/splitData.py b/util/splitData.py
index 9480ba6..52d728e 100644
--- a/util/splitData.py
+++ b/util/splitData.py
@@ -1,37 +1,43 @@
-# utility to split a raw datafile up into n roughly equal parts.
+# utility to split a raw datafile up into n roughly equal parts, keeping all profiles for a given cruise in the same file
 
-import main
 import math
 from wodpy import wod
 
-#filename = '../../AutoQC_raw/quota/quota_all.dat'
-#filename = '../data/quota_subset.dat'
-filename = '../../AutoQC_raw/quota/test/chunk.dat'
+filename = '../quota_all.dat'
 n = 30
 
 fid = open(filename)
 fid.read()
 fileSize = fid.tell()
-chunkSize = int(math.ceil(fileSize / n));
+chunkSize = int(math.ceil(fileSize / n)); # final files should be about this big
 
-fileNo = 0
-start = 0
-end = 0
-
-target = open('split-' + str(fileNo) + '.dat', 'w')
+# identify cruise numbers, profile start and profile end positions for all profiles
+markers = []
 fid.seek(0)
-while not (fid.read(1) == ''):
-    #write next chunk to open target
-    fid.seek(end)
+while True:
     start = fid.tell()
     profile = wod.WodProfile(fid)
     end = fid.tell()
-    fid.seek(start)
-    extract = fid.read(end-start)
-    target.write(extract)
+    markers.append( (profile.cruise(), start, end) )
+    if profile.is_last_profile_in_file(fid) == True:
+        break
+# sort by cruise number
+markers = sorted(markers, key=lambda x: x[0])
 
-    #wrap the file and start a new one once we've crossed the max size
-    if target.tell() > chunkSize:
+# write subfiles
+fileNo = 0
+currentCruise = None
+target = open('split-' + str(fileNo) + '.dat', 'w')
+for i in range(len(markers)):
+    lastCruise = currentCruise
+    currentCruise = markers[i][0]
+    # switch out to the next file when we pass chunksize AND are finished the current cruise
+    if target.tell() > chunkSize and currentCruise != lastCruise and None not in [lastCruise, currentCruise]:
         target.close()
         fileNo += 1
         target = open('split-' + str(fileNo) + '.dat', 'w')
+    fid.seek(markers[i][1])
+    extract = fid.read(markers[i][2]-markers[i][1])
+    target.write(extract)
+
+target.close()
\ No newline at end of file