Referee Joe Ross was one shower short of calling off this desperate struggle for Nationwide Division Three survival.
Surface water drained away but the game still had to wait 80 minutes for its first real shot.
Then the fresh legs of Rovers' sub Paul Tait carried him past his marker Matt Redmile to get in a rather modest shot.
A minute later he went round the Shrewsbury centre back again and this time lobbed onto the bar with the keeper Mark Cartwright beaten.
These were two reasons why Shrewsbury's manager, Kevin Ratcliffe, said he was happy to be going away with a point and a clean sheet.
"We've been struggling a bit away from home and this was never going to be an easy match." he conceded.
"We were the better side in the first half." A willingness to open up the game gave his side a decided edge before the break but this changed when Rovers' static front pair of Giuliano Grazioli and Michele Di Piedi began to run more towards the flanks.
Beaten only twice in 13 games Rovers are pinning their League hopes on their defence and this was their fourth clean sheet in five games.
They should have been put under more pressure after losing right back Danny Boxall to a hamstring injury after 11 minutes but young trialist Sonny Parker came in to deputise well.
Although Rovers were creating few chances Shrewsbury still had to thank two vital tackles for keeping them in the game.
The first was a brave stop by Peter Wilding on Rob Quinn as Rovers kept up the pressure from a corner and then Redmile put in a stern challenge on Piedi at the edge of the six-yard box.
Shrewsbury's best chance of taking all three points came with a retaken free kick 25 yards out and late on.
The second kick was needed when Rovers were guilty of encroaching. Each time though that experienced striker Nigel Jemson hit the ball into the wall.
His lively partner Luke Rodgers picked up a harsh booking and was taken off with a quarter of an hour left.
It was a decision his manager explained to protect him for the run-in although with games in hand and points clear of the bottom five, Shrewsbury are now beginning to look safe.
Like his counterpart Rovers' manager Ray Graydon was relieved to emerge with a point.
He said: "A couple of months ago we would have fallen to a sucker punch like that late free kick but my players are now believing in themselves."