Oil light on!

[SaltyKayak]

I have a '99 225HP Merc Bluewater outboard. On the last trip to the coast, I noticed the oil light start blinking. At first it was intermittent. Today, while testing out the motor, the oil light will be off then will come on steady after about 21 seconds. I will stop the engine and immediately start it again and 21-22 seconds later, the oil light comes on steady. There is good 'smoke' coming out of the exhaust.. good ol 2 stroke blue smoke. I have never let the oil get low. Advice on the possible cause?
thanx, SaltyKayak