The result, though, maintained Grimsby's recent form improvement but left Boston without a home win for two months.
Despite its overall lack of quality, the match got off to a sensational start for the home side when Daryl Clare marked his return from injury with a goal after 20 seconds, striking low past Anthony Williams from a cross by Danny Thomas on the left.
Grimsby's first response came on 13 minutes when Matt Harrold latched on to a loose ball, but his lofted shot was pushed aside by Nathan Abbey.
After those two openings the match degenerated into a scrappy battle for supremacy with neither side making any real in-roads into the opposing rearguard.
Chances remained at a premium as half-time approached, although Grimsby threatened briefly with two feeble shooting efforts by Martin Gritton and Andy Parkinson, neither of which troubled Abbey, plus a rising 18-yard drive from Stacy Coldicott which flew too high.
There was little overall change in the pattern of play in the opening period of the second half - two unprofitable corners for Boston being answered by a wildly high shot from Gritton.
But the visitors finally found a cutting edge to level matters in the 69th minute when Harrold rifled in from 10 yards after Gritton had flicked on a raking pass from the left by Thomas Pinault.
Seven minutes later the Mariners almost went ahead when substitute Michael Reddy weaved his way into the home area, only to see his goal bound shot blocked by Alan White.
Boston, in need of maximum points, threw on all three subs in a late bid to regain the advantage, but their efforts came to nothing as the match ended all square.