diff --git a/projects/planner/src/app/profilechart/profilechart.component.ts b/projects/planner/src/app/profilechart/profilechart.component.ts
index 1a4856dd..4ec0bb18 100644
--- a/projects/planner/src/app/profilechart/profilechart.component.ts
+++ b/projects/planner/src/app/profilechart/profilechart.component.ts
@@ -1,8 +1,9 @@
 import { Component, OnInit } from '@angular/core';
 import { takeUntil } from 'rxjs';
-import { DiveResults } from '../shared/diveresults';
-import { faChartArea, faFire } from '@fortawesome/free-solid-svg-icons';
 import * as Plotly from 'plotly.js-dist';
+import * as _ from 'lodash';
+import { faChartArea, faFire } from '@fortawesome/free-solid-svg-icons';
+import { DiveResults } from '../shared/diveresults';
 import { SelectedWaypoint } from '../shared/selectedwaypointService';
 import { Streamed } from '../shared/streamed';
 import { DiveSchedules } from '../shared/dive.schedules';
@@ -91,8 +92,10 @@ export class ProfileChartComponent extends Streamed implements OnInit {
         this.plotter.plotCharts(this.dive.totalDuration);
 
         // TODO layout jumps to right when switching on/off the heatmap
-        if (this.showHeatMap)
-            this.heatmapPlotter.plotHeatMap(this.dive.tissueOverPressures);
+        if (this.showHeatMap) {
+            const transponed = _.zip.apply(_, this.dive.tissueOverPressures) as number[][];
+            this.heatmapPlotter.plotHeatMap(transponed);
+        }
     }
 
     private hookChartEvents(): void {
diff --git a/projects/scuba-physics/src/lib/Tissues.spec.ts b/projects/scuba-physics/src/lib/Tissues.spec.ts
index 37e261d0..32668c01 100644
--- a/projects/scuba-physics/src/lib/Tissues.spec.ts
+++ b/projects/scuba-physics/src/lib/Tissues.spec.ts
@@ -64,7 +64,7 @@ describe('Tissues', () => {
             // simple depth conversion at surface
             const tissues = Tissues.create(1);
             tissues.load(segment, StandardGases.air);
-            const saturationRatios = tissues.saturationRatio(2, 1);
+            const saturationRatios = tissues.saturationRatio(2, 1, 1);
             expect(saturationRatios[0]).toBeCloseTo(1, 8);
         });
 
diff --git a/projects/scuba-physics/src/lib/Tissues.ts b/projects/scuba-physics/src/lib/Tissues.ts
index 70e8c1f5..1daa4ef0 100644
--- a/projects/scuba-physics/src/lib/Tissues.ts
+++ b/projects/scuba-physics/src/lib/Tissues.ts
@@ -275,7 +275,7 @@ export class Tissues {
                 return t.gradientFactor(ambientPressure);
             }
 
-            return t.pTotal / ambientPressure;
+            return t.pTotal / ambientPressure -1;
         }).value();
     }