3x 7mn row with 3mn recovery paddling in between
1st @24spm (1528m) 30s on / 30s off
2nd @26spm (1560m) 1mn on / 1mn off
3rd @28spm (1536m) 1’30 on / 1 off / 1’30 on / 1 off / 1’15 on ... (not sure of the last scheme)