Grant Line Canal is a tidal slough within California's Sacramento-San Joaquin River Delta, connecting to Old River and Salmon Slough. It is a flatwater waterway suitable for novice paddlers, with conditions heavily influenced by the daily tidal cycle. The tidal range can be significant, with a typical range of approximately 4 feet between high and low tides. Paddlers should consult specific tide predictions for the Grant Line Canal (Drawbridge) station to plan their trips, as the current direction and speed are dictated by these tides. A notable access point is Rivers End Marina on Old River, which charges a launch fee and provides facilities including restrooms and a store. From there, paddlers can enter Grant Line Canal. A significant hazard is the presence of invasive water hyacinth, which can form dense mats that nearly block passage and complicate navigation, especially in narrower channels. Additionally, a permanent rock barrier exists east of the Tracy Boulevard bridge, requiring a portage; state personnel are present to assist with this. The area offers a mix of landscapes, from levy banks lined with tule and oak trees to more natural riparian habitats reminiscent of the Cosumnes River Preserve. Wildlife sightings include egrets, buffleheads, coots, hawks, and owls. A unique sight reported is sheep and goats wading in the water to feed on hyacinth. The canal and its connecting sloughs are used by powerboats, and paddlers may encounter hunters in season, particularly in areas like Mountain House Creek. Due to the hyacinth and the potential for blocked channels, exploring smaller sloughs and attempting to circumnavigate islands carries a risk of getting stuck.