On Rotosound's official website, they list the RS66LD Swing Bass strings as the strings Chris Squire used throughout his career. They noted "Sometimes we will make up Chris’s custom extra long scale Swing Bass strings!"

In this January 8, 2020 article by Guitar World highlighting Squire's life and career, a segment is featured on his choice and usage of Basses over his career.

"Driving through the sound"

"Chris Squire recorded or performed with more than a dozen bass...

Chris Squire says about the Fender Jazz in this video for Premier Guitars (5:30), "I've used that quite a bit on Yes recordings over the years... it's on 'Parallels'..."

At 13:00, Chris's bass tech Richard points out two Marshall bass heads, that judging by the facing and controls, are early Super Bass's. The lower one is said to be from 1965 and the other is a back up that has apparently never needed to be used. After this it's said that he blends the Marshall w...

In this rundown, Chris's bass tech describes the unit as a 'Maestro fuzz box' at 15:56, although with controls such as brass volume, bass volume and sensitivity and the unusual layout of the knobs down the right hand side of the pedal it must be an original Brassmaster from the 60's

At 6:28 of this "Rig Rundown" with Premier Guitar, Chris shows us his triple neck bass guitar. In this accompanying article "Premier" writes that he uses thi...

Squire's official site states that he uses an MPC Electra Bass live with Yes. A clear picture of this bass in this video is shown at 0:38.

According to the official Yes website, bassist Chris Squire played a Gibson EB-1 bass guitar.

Full article here.

"Squire, who felt that certain effects were better matched with neck or bridge pickups, rewired his Rickenbacker with stereo outputs in the early ’70s. Onstage, he used a boatload of vintage effects, including Maestro Fuzz-Tone, TC Electronic Stereo Chorus Flanger, TC Nova Reverb, Boss OC-3 Super...

In this image, Chris Squire can be seen playing a Gibson Thunderbird Non-Reverse.

In this Rig Rundown article, it is stated that Squire uses a Mouradian bass, pictured here.

The Rickenbacker RM1999 was the British Import equivalent to the 4001 with notable differences being the lack of binding, and dot inlays instead of the triangle inlays. The RM, like with other 60s British Import Rickenbackers, stands for Rose Morris.

Squire's official site states that Chris uses a Ranney bass. In this video, the bass can be seen at 0:59.

Richard Davis, Squire's guitar tech, states, "Actually, Chris used two bass pedal sounds in the 70's. One being the original Moog Taurus Pedals and the other being an old Italian electronic organ supplemental pedal board that was made by Dutron. Nowadays, Chris' original blend of these two inst...

On Chris Squire's Tech Notes section of his official site, there are photos of his "Fish Out of Water" Rickenbacker 4001 bass.

In the Relayer Tour Programme from 1975, Chris Squire lists his instrumentation. "Instruments: ... Ampeg 4 string stand up electric..."

Chris Squire has used this bass according to the official Lakland site.

At 2:47 of this acoustic performance of "Roundabout" by Yes, Squire can be seen with a fretless version of the Martin BCPA-4.

Squire can be seen in this photo with a Gibson Les Paul Triumph Bass among his other basses.

At 16:18 a Mutron iii+ can clearly be seen on Chris's pedalboard.

Further down on this page, in the touring programs, it is mentioned that Squire owned a Gibson Ripper.

At :54 of this Steve Hackett performance, Squire can be seen playing a Spector Coda 5.

In this '70s concert photo, Squire can be seen playing his original Wal Triple-Neck Bass, before he had the Kid's Guitars replica made.

The bottom-neck is a 4-String fretless Bass, the middle-neck is a 4-String standard Bass, and the top-neck is a T-style guitar that Squire modded into a ...

Before Chris used the Ampeg SVT 2-Pro head, he used these heads. (Similar name, very different amp.)

According to the official Yes website, bassist Chris Squire owned a Danelectro Longhorn 6 string bass while playing with Yes.

Full article here.

Squire can be seen playing a Carvin LB-76A in this photo.

Richard Davis, Squire's guitar tech, states, "Chris’s rig…Marshall 100 watt head with a Marshall 4 x 12 speaker cabinet (over there), Two Ampeg SVT-2 Pro heads, Two SVT- 8 x10 speaker cabinets, an SWR amplifier head for the Bass Pedals, and an SWR 2 x 15 speaker cabinet," on Squire's ...

Squire can be seen in a photo on this page with a Guild Jet Star II behind him.

It is stated on Squire's official site that he used Dewtron Mister Bassman bass pedals.

"Squire, who felt that certain effects were better matched with neck or bridge pickups, rewired his Rickenbacker with stereo outputs in the early ’70s. Onstage, he used a boatload of vintage effects, including Maestro Fuzz-Tone, TC Electronic Stereo Chorus Flanger, TC Nova Reverb, Boss OC-3 Super...