Jack Nitsche destroyed the surf music genre with his "The Lonely Surfer" which included French Horns, violins, cellos, and trombones and choral voices. It was a very sad day and Surf music hasn't been the same since.
I went to high school (Class of '64) in Huntington Beach during that era and the "Surf Sound" that Dick Dale got with the Dell-Tones was lots of reverb, thudding bass with dead strings and lots of power.
If I'm not mistaken, I believe the 'double-kick' bass drum was also brought into a lot of use too about that time for more thump and drive.
I was either out surfing the Wedge, The Trestles, going to classes later on at OCC or playing bass at The Rendezvous (on Balboa Peninsula) or The Pavalon (@ the Huntington Beach pier)
There were other groups (The Surfaris, Eddie & The Showmen, The Chantays, The Pyramids, The Crossfires, The Trashmen, The Mojos (where I played bass), The Bel Airs and many more) - but when I was gigging those days we had to keep the bass-line heavy for the dancing and the 'heat on the floor' as we called it. The floors literally bounced from the music.
Blonde surfer chicks - yeah! I digress.
If the bass could not be heard to 18th Street on the Peninsula or down to The Wedge from The Rendezvous down at the Fun Zone - then it wasn't loud enough. Balboa Island always had a free show that they could hear all over the place though. We shook Bal's windows and then the cops would come -- ah! good ol' days!
The old folks on "The Island" on Mom-n-Pop sightseeing tours didn't like that free 'noise' and they stopped going to The Island. Good! More Island for us!
A few times we used dual basses in the lineup just to shake the place more.
I think one of the most innovative groups was The Ventures. Dick Dale had his Lebanese/Polish musical background and his quad-staccato picking to get him his unique sound, but The Ventures did it with whammy bars, reverb and their Mosrite Guitars.