Your steps are fine. No need to put it in gear. Run it till the engine reaches normal operating temperature to ensue the thermostat has opened. Are you trailering the boat, lift, other? The salt in the Bay is you bigger concern than dirty water. Itís up to you some flush after every outing others once a month. If youíre trailering it itís easy to do it once a week.
1997 2400 SCR
5.7 Vortec / Bravo 2