The stalemate seemed inevitable as both teams looked very comfortable in possession but had very little cutting edge.
Dele Adebola put in one of his best games in a City shirt, yet still the Sky Blues struggled to carve out any chances.
A mix up between Youssef Safri and Gavin Ward in the third minute saw the ball only partially cleared as far as Gavin Mahon whose volley from 25 yards flew narrowly wide with Ward stranded.
The Hornets looked more dangerous in the opening stages, and Bruce Dyer should have done better when Paulo Vernazza's cross whistled across the face of the goal after ten minutes.
Coventry's first effort on target came in the 20th minute from Gary McSheffrey, looking lively on only his second game of the season for City, when he turned 20 yards out and fired in a fierce drive, but it was straight at Lenny Pidgeley.
City then came inches from breaking the deadlock when a screaming 25-yard effort from Safri rattled Pidgeley's left-hand upright.
Dean Gordon surprised everyone except Pidgeley with a 35-yard effort in the 47th minute and the impressive Hornets' keeper saved well.
Moments later Vernazza also tried his luck with a long-range effort after skipping away from Safri's tackle but his low drive did not test Ward.
The visitors had more possession than they knew what to do with in the second half but Calum Davenport was imperious at the heart of Coventry's defence and there was simply no way through for Watford.
Julian Joachim missed a gilt-edged chance to snatch a late winner when he was played through by Patrick Suffo, but he screwed his effort wide under pressure from Pidgeley.