ETOBICOKE, Ontario — Strait of Dover established himself as a contender for the June 24 Queen’s Plate with a decisive score Saturday at Woodbine in the $156,300 Marine Stakes. In his first race around two turns, Strait of Dover tracked the leading Incredicat through moderate fractions in the 1 1/16-mile route for 3-year-olds. Strait of Dover assumed command exiting the far turn, and then drew off through the stretch to prevail by 6 1/2 lengths, in 1:43.44. Classic Bryce outran lukewarm favorite Holiday Promise by three-quarters of a length for third in the six-horse field.  Justin Stein rode the British Columbia-bred Strait of Dover for trainer Danny Vella. “He’s a really nice horse,” said Stein. “He’s got a ton of confidence. He loves being out here, and he loves his job. He wants to destroy everything in sight.” Strait of Dover returned $13 in his third straight victory, and won $90,000 for Canyon Farm.