No longer boating but if it makes you feel better, Mystik is produced by a LARGE oil/gas company and is by no means a second tier product. Mystik is produced by/is a Citgo brand.
I use their HEDO in my 14 Road King with terrific results and UOAs.
I use it on the 5 liter Chevrolet engine in my 2455 Bayliner. No issues, but I have used other oils in the past and did not have any oil related issues then either.