+ /* Time markers: at most every 5 min, but no more than 12 markers
+ * and for convenience we do 5, 10, 15 or 30 min intervals.
+ * This allows for 6h dives - enough (I hope) for even the craziest
+ * divers - but just in case, for those 8h depth-record-breaking dives,
+ * we double the interval if this still doesn't get us to 12 or fewer
+ * time markers */
+ i = 0;
+ while (maxtime / increments[i] > 12 && i < 4)
+ i++;
+ incr = increments[i];
+ while (maxtime / incr > 12)
+ incr *= 2;
+