How did Bart get to Midway Island?

FROM WHO-KNOWS-WHERE

No indication is given in the episode for Bret or Bart Maverick's back trails. But late in 1871, it is likely they were still searching across the West for the Tall Man, who could clear their names of murder back home in Texas.[1]

SAN FRANCISCO

Bret arrived in San Francisco, probably for the  first time, a while before the beginning of "The Wrecker." While playing poker with some of the city's leading entrepreneurs at the Hotel Bossert, he learned of the Ring, and began to plan a way to buy his way in. Feeling that he could use some trusted help in his endeavor, he sent for Brother Bart to join him. Bart, arriving shortly after Bret's summons, found himself also visiting San Francisco for the first time.[2]

MIDWAY ISLAND

In San Francisco, Bart chartered the Norah Creina to take him to the Flying Scud beached at Midway Island. Aside from a bout of sea-sickness, Bart's 3,200-mile ocean voyage was direct and uneventful.[2]

SAN FRANCISCO

The week after Bart sailed for Midway Island, Brother Bret had cause to sail after him aboard a British man-of-war. By the time the man-of-war was four days away from Midway, it came upon Bart and Paul Carthew's jolly boat, adrift at sea. The man-of-war rescued them and, without sailing on to Midway, returned directly to San Francisco.[2]

TO WHO-KNOWS-WHERE

Upon Bret and Bart's return to San Francisco, they were able to settler their debts. Bret decided to move on, and is likely to have soon found the Tall Man, with whom he was able to travel to Texas and clear his and Brother Bart's name of the murder charges against them there[1] since by May of 1872, Bret was able to travel with impunity in the state of his birth.[3] Bart, however, chose to remain in San Francisco for a time, where he soon made the unfortunate acquaintance of Van Buren Kingsley.[4]