Dirt ramp on Day Loop will work fine for you, I drop my 10' Zodiac w/9.8hp in there somewhat regularly.
If you're sticking to JB, I'd go by land. If you want to dive elsewhere during the same trip, use the boat and launch from Day Loop. You can boat over to Edds, tie off to his pier, and get the 4-wheeler back down to the pier to load up your tanks to top-off ontop of the hill.
