The team with the worst defensive record in the Championship in 2004-05 defended resolutely against a second-half onslaught to earn their sixth draw of the campaign.
They may have turned it into a victory if they had made the most of one or two of their chances in the first half, including youngster Gary Roberts' shot against the post when he was clean through on goal.
Crewe also protested furiously when they felt they should have had a 14th minute penalty when Steve Jones was scythed down in the box by Junior Osborne, but the referee's assistant had raised the flag against the striker for offside.
David Vaughan was the pick of the home side with some strong running and the Welsh Under-21 international went close to breaking the deadlock when he powered a right-foot drive inches past the post just before half-time.
But Watford debutant Trevor Benjamin, on loan from Peterborough, went close with a couple of early headers and Anthony McNamee volleyed Paul Devlin's cross just over.
Watford stepped up the tempo after the break and came close to edging in front when Benjamin took the ball off Vaughan and turned and fired only to see Ross Turnbull make a smart save.
Benjamin glanced a header wide from a corner as Watford posed a significant aerial threat and the hosts were indebted to keeper Turnbull again when he parried Clarke Carlisle's header and then saw Vaughan and Kenny Lunt scramble the ball off the goal-line.
Jordan Stewart's thundering volley was heading for the top corner before Turnbull turned it away.
The only sour note of the afternoon for the goalkeeper on loan from Middlesborough was when he was forced off with a knee injury after he came off worse after a challenge with Benjamin.