Steady state:

40 minutes:
#1.10 min @ 22 for 2 min (+19), 22 for 2 min (+14)
(yes the rate stays the same but the effort must get more intense per stroke.)
REST: 1 minute paddle
#2. 10 minutes: Same
REST: 1 minute paddle
#3. 10 min @ 24 for 2 min (+17), 24 for 2 min (+12)
REST: 1 minute paddle
#4. 10 min: SAME