The phrase "rising tide" means that everything is improving or getting better together. It suggests that when one thing improves, it benefits other things as well, leading to overall progress. Full definition
It warned of a «rising tide of mediocrity» in American public schools and asserted that the nation was failing to meet the need for a highly - trained, competitive workforce. (americanradioworks.org)
In the spirit of rising tides lifting boats, states that did well overall also generally showed gains at the high and low ends of the achievement distribution. (educationnext.org)
Unfortunately, just like rising tides raising all boats, the mentality of a «B» player is catchy. (rave-reviews-home-staging.com)