Gerry Rodrigues - Tower 26 Workout

This is a workout that I use form Gerry Rodrigues - Tower 26:
1) Warm up - 10 mins or so
2) 4 x 200m Pulling (snorkel and pull buoy, increasing efforts)
3) Main A - 8 x 100 (85% effort, 5-10 seconds interval)
4) 2 x 400 Pulling (snorkel and pull buoy - ankles together)
5) Main B - 8 x 100 (full out, 1 min intervals)