diff --git a/rowers/datautils.py b/rowers/datautils.py
index 298280d4..d085f1c8 100644
--- a/rowers/datautils.py
+++ b/rowers/datautils.py
@@ -175,8 +175,14 @@ def getmaxwattinterval(tt,ww,i):
         try:
             t_0 = tt.ix[indexmax]
             t_1 = tt.ix[indexmax-i]
-            deltat = 1.0e-3*(t_0-t_1)
-            wmax = w_roll.ix[indexmax]
+            deltas = tt.ix[indexmax-1:indexmax].diff().dropna()
+            testres = 1.0e-3*deltas.max() < 30.
+            if testres:
+                deltat = 1.0e-3*(t_0-t_1)
+                wmax = w_roll.ix[indexmax]
+            else:
+                wmax = 0
+                deltat = 0
         except KeyError:
             pass
     else: