Generally the Glengarry is considered a military or bandsman's hat. For civilian wear a Balmoral is to be preferred. Ultimately, however, the choice is yours. A few weeks ago at the Greenville Highland Games in South Carolina, Lord Glasgow (chief of Clan Boyle), Harden of Cowdenknowes, Squire of Rubislaw, and Yours Truly, all wore Panama hats the minute bonnets were no longer required.