vessels of and drawing can still proceed along the estuary at high water, and can travel inland as far as fulney lock. they cannot pass through the lock as it is only and at normal summer water levels, can accommodate boats drawing . the river is officially navigable to the point at which the folly river joins it, but the length of boats allowed on this section is restricted to long, considerably less than the lock dimensions would suggest. navigation on this stretch was severely restricted by four mile bar footbridge, which provided just of headroom, but this was increased when a new single-span arched bridge was installed in early 2007 by the lincolnshire waterways partnership. smaller boats such as canoes, which can be carried around obstructions, can continue up to stamford, but they must use the old course of the river through the deepings, rather than the maxey cut.