Preheat oil in a large pan with tall sides, to 350˚F.
Cut each zucchini in half crosswise, then stand each piece up and cut each pieces into quarters (until you have 16 short spears).
Line the zucchini spears onto a plate and sprinkle with 2 tablespoons salt.
Allow zucchini spears to sit for 15 minutes (this will draw water out of the spears, allowing them to crisp up better).
Pat zucchini down with paper towels or a clean kitchen towel and transfer to a clean plate.
In a shallow dish combine flour, garlic powder, and onion powder. Stir together.
In another shallow bowl combine eggs and 2 tablespoons water. Whisk together.
In a third shallow dish, spread panko breadcrumbs.
Dredge zucchini spears in the flour mixture and shake to remove excess.
Then dip each spear into the egg mixture until fully coated.
Finally, dredge the spears in the panko breadcrumbs until fully coated. Shake off any excess.
Fry spears in hot oil, in batches, for 3 to 4 minutes or until well browned and crisp.
Transfer to a cooling rack lined baking sheet and season with salt.
Repeat frying until all spears have been fried and seasoned.
Transfer spears to a serving platter and serve with marinara sauce for dipping.