Discs will be flying around Amherst Regional this weekend, but there will be no need to contact the authorities.

These discs will be caught.

The 25th Amherst Invitational, the longest running high school ultimate tournament in the nation, kicks off Saturday morning and will conclude Sunday afternoon.

This year’s event is the largest on record as 35 teams will take to the fields at Amherst.

Contributing to the large field was the addition of a second girls division, Girls B.

“There’s been a big push to increase the numbers of girls playing ultimate,” Amherst girls coach Josh Nugent said. “Girls has lagged behind boys ultimate. After the tournament last year we hatched a plan to add a Girls B Division.”

The competitive Girls A Division features the seven-time defending champion Hurricanes. The program’s junior varsity team is also in the mix, as is Fryeburg Academy (Maine), Longmeadow, Lower Merion (Pennsylvania), Northampton and PVPA.

Amherst beat Watchung Hills, 15-8, in last season’s final. Lower Merion beat PVPA, 14-5, in the third-place game.

“This is the highlight of our season,” Nugent said. “We have other tournaments coming, but this is the home court.”

Northampton went 2-2 in pool play last season and will look to improve on their sixth-place showing.

“I think we expect to be challenged with a lot of highly skilled teams coming in,” Hamp girls coach Clarissa Lyons said. “Our highest priority is bringing intensity and aggressiveness.”

The inaugural Girls B Division is a collection of up-and-coming teams: Amherst JV B, Columbia High School (New Jersey), Lincoln Sudbury, Newton North, Longmeadow JV and Sharon High School.

Boys tournament

Half of the Open A Division final four is back.

Pennsbury returns to defend its crown, but runner-up Radnor is absent from the field.

Lexington, which fell to Amherst in the third-place game, is also absent.

That leaves Amherst JV A, Columbia, Four Rivers Charter, John Jay (New York), Lincoln Sudbury, Lower Merion, Needham and Northampton vying for spots in the final four.

Amherst should contend for the title. The Hurricanes won the Paideia Cup in Atlanta last month.

“I think we’re definitely ready,” third-year coach Joe Costello said. “We’re the one seed for the first time since I’ve been coach. We’re expecting to go out there and play our game. Hopefully win.”

The boys Open B Division includes Amherst JV B, Amherst Middle School, Cambridge School of Weston, Falmouth, PVPA, Sharon, Somerville and Williston Northampton.

Pool play in all divisions is scheduled to start at 9:30 a.m. on Saturday. The tournament continues Sunday at 8:30 a.m.

The Girls A Division final is at 1:45 p.m., followed by the Open A final at 3:30.

Weather and field conditions could alter the schedule.