The hosts came closest to finding a winner when Brandon Khela moved inside on his left-foot and fired through a number of bodies only for the Hornets' keeper to push the ball around the post.
Teammate Jordan James also tested the opposition stopper with an effort destined for the top corner as Blues gave everything to break down a low block.
However, it was not meant to be as a defensive display from the away side meant the spoils were shared at the Trillion Trophy Training Centre.
But speaking to BCFC.com post-match, Assistant Coach Martyn Olorenshaw was keen for his players to take real heart from their performance and how it continues to prepare them for future challenges.
He explained: "It is a bit of a compliment. I don't know the makeup of their team, but they certainly changed the way they play because of us. We just had to not get frustrated. It is something that the boys could come across again. In senior football, teams are more organised and you have to try and find a way to unlock it.
"They were tough and really stubborn. We did enough to win the game and their keeper made a couple of really good saves."
Olorenshaw was also pleased with how the players showed maturity when dealing with the task at hand, whilst not neglecting their duties during a test that required real patience.
He said: "The boys really stuck at it and they didn't really get over frustrated with it. They stuck to their task and put a lot into the game. It maybe wasn't meant to be on the day.
"We didn't expect them to defend as deep as they did. They were well organised and stuck at their task. They were delighted with the 0-0, we had all of the ball."
Following the draw with Watford, a trio of games remain this term for the Under-18s and the Coach believes that the objective remains the same.
Olorenshaw said: "We have three games so let's accumulate as many points as we can and let's see where it takes us. There's going to be twists and turns and let's focus on Cardiff on Saturday.
"I think they will try and play, it could be a good game. I'm expecting a tough test away from home and they certainly are not going to make it easy for us. We will do everything between now and Saturday to make the players ready."
Blues: Mayo, Sullivan, Fogarty, Nguepissi, Barratt, James, Hall, Patterson, Khela, Wakefield, Hamilton (Manton 9).