Todd Watson was the pick of the bowlers in the first innings, picking up five wickets for 43 runs off his 13 overs.
The only real resistance from Wanganui came from the bat of Max Carroll, who was unbeaten on 53.
Hawke's Bay's innings was anchored by opening batsman Jake Smith, who scored an unbeaten 131 off 187 balls.
Castle said Smith's innings iced the game for Hawke's Bay:
"On the back of an opening batsman scoring 100, you'll always find yourself in a strong position.
"It's great to have [Smith] back in the team, he's been the captain for five years before this year."
Izaiah Lange posted a quickfire 63 off 66 in support before he was bowled by John Beale, who also took the wicket of Graeme Tryon with his next delivery.
There was to be no hat-trick for Beale though, and Ross Kinnerley was the only other Wanganui bowler to take a wicket with his three scalps coming for 80 runs.
Wanganui were rolled for just 82 runs in their second innings, with the final wicket falling only three balls after the lunch break.
The final batsmen out Hunter Morrison was caught by Matt Edmondson off the bowling of Kyle Gardiner for 13, just five runs short of the innings-high score posted by Hadleigh O'Leary.
That was the second of Gardiner's two wickets, with debutants Fred Mowat and Liam McCarthy picking up braces as well from each of their six-over spells for just nine and 12 runs respectively.
Castle said the performances of that pair, along with another rookie in wicketkeeper Kurtis Weeks, showed they are all capable of making the step up to senior representative cricket.
