It seems that the thing affecting my paddling technique is my stomach and core muscles. Junsheng mentioned in the last training session that I tend to unwind my body too early.
That was merely a symptom. The reason for this? My stomach and core muscles aren't strong enough, I tried paddling slow, pausing just before the beginning of each stroke, making sure my body does not unwind until the blade is fully submerged. What I noticed was me being unable to hold that position for long. My more powerful muscles are weak. Damn, I need to go back to my daily fitness regime.
My right arm is also too low, a bad habit for the lower angle paddling style I'm used to. This explains why my boat tends to move off course after a while.
Also said "Hi" to a caucasian guy paddling around Kallang in a surf ski. Cool. Didn't realise there was more than 1 surf ski in Kallang.