This does not look like a well thought out idea. From Sam Fraser at responsiblestatecraft.org:
Calls for a ‘coalition of the willing’ to establish a ‘maritime corridor’ are designed to obfuscate the dangers that it will create.
Since Russia invaded Ukraine in February, relatively few in the Western commentariat have been willing to call for the United States to engage in direct war against Moscow. The reasons for this caution are obvious — Russia is a nuclear state, and has a military that, its recent underperformance notwithstanding, is still vastly more formidable than any recent target of U.S. military intervention.
Yet despite — or perhaps because of — this general resistance to direct U.S. involvement, many commentators and politicians have come up with more underhanded proposals for American military intervention.
Most notably, this began with widespread calls for the United States and NATO to establish a “no-fly zone” over Ukraine early in the war. In spite of its innocuous and legalistic name, the Biden administration soundly rejected this proposal as its enforcement would rather obviously entail shooting down Russian aircraft, which in turn would lead to a wider war.
More recently, as the danger of a global food crisis made worse by the loss of grain exports from Ukraine and Russia has increased, new calls have emerged for the United States and allies to use naval power to ensure that Ukrainian grain can safely transit the Black Sea.