In rafts, canoes and a 40-foot yacht, advocates will draw attention over the next month to the Tuolumne River and downstream waters.
The second annual Paddle to the Sea will start in the Sierra Nevada on Friday and pass through Modesto on its way to San Francisco Bay.
Participants are signing up to cover one or more of the 18 segments on the 241-mile route. They pay entry fees and must raise at least $50 in donations for the Tuolumne River Trust, which is putting on the event with numerous sponsors.
"We want to build support and stewardship for the Tuolumne River," said Jesse Roseman, the Central Valley program director for the group. "We feel that the best way to do that is to get people out on the river."
The trust works to enhance fish and wildlife habitat and recreation on the Tuolumne. Most of it is diverted by the Turlock and Modesto irrigation districts and San Francisco.
Organizers of Paddle to the Sea hope to top the 250 people who took part last year.
The event will be held on 23 days from Friday to June 5. The cost for most days is $10 for trust members and $25 for others. It is substantially more for overnight trips on the whitewater stretch just above Don Pedro Reservoir, and for a 90-mile yacht cruise from Stockton to Oakland.
The whitewater trips, starting about 10 miles east of Groveland, will kick off the event. They will be followed by powerboat cruises across Don Pedro and by canoes and kayaks in the Stanislaus County part of the river.
It is running fairly high this spring, Roseman said, so rafts might be used below Don Pedro for safety's sake.
Kayaks and canoes will continue the trek to the Tuolumne's confluence with the San Joaquin River and into the Sacramento-San Joaquin Delta. The yacht cruise will feature speakers on delta issues.
The event will end with sea kayakers pulling into Pier 39 in San Francisco.
Three people have signed up to do the entire route -- Owen Segerstrom of Sonora, who did it last year; Brian Coggan, a Bay Area resident who paddled the entire Mississippi River last year; and Andrew Cushman, a kayaking guide from the Bay Area.
Bee staff writer John Holland can be reached at email@example.com or 578-2385.