Thor, Orion, Demon, Omac cover by Larry Houston. Spectre back cover art by Al Milgrom. News and information on comics coming from DC, Marvel, Gold Key, Visual, Star Reach, Harvey, Warren, and Charlton. Includes plot synopses and cover art. Spider-Woman article by Marv Wolfman. Letters from Gary Brown, Roy Thomas, and Kim Metzger. Founded by Jerry Bails. Published by Street Enterprises. Feb. 1978. 75 Cents. 32 pgs. B&W, 5.5-in. x 8.5-in. Cover price $0.75.
It's not one of they guys named. It's supposed to be featuring Kirby heros, but I can't track down which one it is. Probably someone from New Gods like you said.
I wonder if perhaps a wizard who has used animagus powers to transform might have been able to ride on the boat. In that case perhaps Sirius rode along with his brother. Not sure why Sirius wouldn't have told anyone that...