You can hit launch mode on a rafting trip this summer and feel like you’re being shot out of a cannon.

Light the fuse and stand back.

As the rafting season gets under way, the outlook matches or exceeds the biggest water seasons in the past 30-plus years, including 1983, ’86 and ’98. Coming after years of drought, conditions are beyond euphoric for those who love rafting, kayaking and river running.

Except that not everyone buys into the getting “shot out of a cannon” deal.

Ratings for many rapids have been upgraded to the highest level and — in a new industry trend — several rafting companies have raised minimum age requirements from age 7 to 12 until flows recede to more traditional levels.

“With all the water, we’re treating Class III runs like Class IV,” said Nate Rangel of Adventure Connection out of Coloma. “We want to take the safety precautions so we can run the best possible trips. We don’t want any trips where folks are over their heads. The bulk of the snow is still up there. We’ll take it as it comes.”

That said, the opportunity for river-based recreation is almost unprecedented. In the California Department of Water Resources’ May 1 survey, the water content of snowpack statewide was 181 percent of normal, and 207 percent of normal for areas of the southern Sierra Nevada.

Snowmelt is the fuel that drives the rafting season, but some rivers have so much water thundering through the canyons that the season openers are delayed. In some extreme cases, the warm weather is creating river flows so strong that even rafting experts are sidelined.

The Middle Fork American River, with its celebrated Tunnel Chute rapid, won’t have accessible flows until July — and then they might be available through mid-September. That’s a mind-bender. Usually, the first runs of the year can be done there over Memorial Day weekend.

The Truckee, Tuolumne, Merced and many other rivers will face very high water levels from peak snowmelt this week. Those rivers and others, like the Klamath at Hells Corner Run, are looking at summer-long seasons once things calm down.

In another wild affair, the Upper Kern, the once-epic run in the southern Sierra left for dead because of low flows since 2012, will be fed by a snowpack as high as 236 percent of normal on the flank of Mount Whitney. The Class IV-plus Upper Kern is a go as spring takes hold on Whitney.

Not all rivers are created equal, and not all rafters are created to master all rivers. The key is to match skill level with water level.

Here are the best of them, from difficult to easy, and the latest news from each river. Adventure Connection’s Rangel networked with rafting guides and companies from across California to assist in this report:

Expert challenges

Cherry Creek, Stanislaus National Forest: Trips through Cherry Valley, a technical paddle through a prolonged rock garden, a wild affair, dangerous for some, will start this month.

Forks of the Kern, Sequoia National Forest: The Kern looked like a creek for years, but now it’s back. With a huge snowpack in the watershed, the Kern has a rare chance for greatness.

Cal Salmon, Shasta-Trinity National Forest: Summer is approaching, but only this week has the snowmelt started in the high country of the Trinity Alps. The Cal Salmon run, which spans from Forks of the Salmon down the canyon toward the Klamath, is going to be the bucking bronco of whitewater.

Experienced experts, Class IV runs (with guides)

Upper Klamath, California-Oregon border: The classic run through Hells Corner, featuring the Class V stretch from Caldera through Satan’s Gate, will be a go all summer.

Tuolumne, Stanislaus National Forest: One of the top runs anywhere in the Western U.S. will be from the put-in at Meral Pool downstream through a mix of rapids and catch-your-breath slicks en route to Class V Clavey Falls, the legendary cascade. For the first time in years, rafting outfitters are booking trips through Labor Day, and the season could even run into fall. In the early season, high water has kept rafts off the water some days.

North Fork American, El Dorado County: This run cascades through a gorgeous wilderness canyon. In the past six weeks, the water has often been too high to run safely, but on Sunday and Monday finally was low enough to run. “We expect a good season through at least June,” Rangel said.

Middle Fork American, Placer County: The best projection is the Middle Fork. Tunnel Chute, its landmark drop, and its series of Class IV action will be ready to raft in July. For now, it’s way too high, rough and rowdy. Once in gear, it will be good through mid-September.

Merced, Highway 140 out of Yosemite: The Briceburg section is usually the favorite for pro rafting trips, but it’s still too high. Instead, for those in this region, head to Yosemite Valley and watch the waterfalls. Once the Merced settles down, it will be good for most of the summer, through mid-August.

North Yuba, Yuba County: Expect good rafting flows into mid-July. Most put-in at the Union Flat Campground.

Family-style runs

South Fork American, El Dorado County: The most popular rafting destination in California could break all records. The river will be in top shape through October, believe it or not. “We’ve got so much water, it’s very close to the ’83 levels, the highest on record,” Rangel said.

Kings, Fresno County: After being close to zilch for five years, this summer will be an exciting season, with rafting flows projected through August.

Lower Kern, Kern County: Mount Whitney’s giant snowpack will feed the Kern watershed through September.

Upper Sac, Mount Shasta: This is a great entry-level river right now for inflatable kayaks and rafts, with flows ideal at 2,200 cubic feet per second. It’s often done by now, but this year it looks to stay in shape well into June.

Entry, party runs

Trinity, Shasta-Trinity National Forest: A great, easy, low-cost Class II-III run to Big Flat will be in good shape all summer.

Cache Creek, Yolo County: The closest rafting to the Bay Area includes a wilderness run through foothill country with a Class III rating, good for beginners or do-it-yourself style.

Truckee, Placer County: The party run, the 5-mile float from Tahoe City in small rafts and inner tubes, has no opening date. A huge snowmelt is imminent and Lake Tahoe is expected to overflow into the river well into summer.

Lower American, Sacramento County: The biggest party river in Northern California, the site of infamous “Rafters Gone Wild,” located from Fair Oaks to Sacramento, has too much water and won’t be in business for a month or so. Look for a July Fourth launch.

Tom Stienstra is the outdoors writer for The Chronicle. His outdoors report can be heard at 7:35 a.m., 9:35 a.m. and 12:35 p.m. Saturdays on KCBS (740 and 106.9). Email: tstienstra@sfchronicle.com.

Rafting outfitters

Adventure Connection, Lotus: (800) 556-6060, http://raftcalifornia.com

River Runners, Lotus: (530) 622-5510, www.riverrunnersusa.com

American River information, Coloma: www.theamericanriver.com

Tuolumne River Outfitters, Groveland: www.tuolumneriveroutfitters.com

River Dancers, Mount Shasta: (530) 925-0237, www.riverdancers.com

Zephyr, Columbia: (800) 431-3636, www.zrafting.com.

Kern River Outfitter: (760) 376-3370, https://kernrafting.com

Bigfoot Rafting, Big Bar: (530) 629-2263, www.bigfootrafting.com

Cache Canyon River Trips: (530) 796-3091, www.cachecanyon.com

Note: Many of these outfitter websites include several rafting companies that run many different rivers in their areas. This is a selected listing. Many other rafting outfitters are available.

Water safety

Know the water: Sudden immersion in cold water can stimulate the gasp reflex .

Know your limits: People who swim in open water often tire quickly .

Wear a personal flotation device: In the past four years, there have been 132 drownings; the victim wasn’t wearing a life jacket in 104 of them.

Wear a wetsuit: Even in hot weather, rivers are often very cold from snowmelt; it is often advisable to wear a wetsuit or dry suit when rafting or kayaking.

Parental supervision: Appoint a designated watcher, taking turns with other adults, to keep an eye on youngsters when near water or on a boat .

Information: Division of Boating and Waterways, www.dbw.ca.gov.