Well, being both a photographer AND a surfer for more than 20+ years I feel I May be qualified to speak
First off, yep, the Nikonos route is viable one, BUT, getting good to great shots depends highly on your own water ability. Getting into the best position for the best action is very demanding and will require a lot of practice, but this is quite fun since you're swimming around. In California the final section where the wave ends gives the surfer a good chance to do some sort of big move, and that position can be figured out fairly easily, and this often may be in knee to waist high water so it can be accessed easily as well. On larger days this zone can be in deeper water so that increases the difficulty. As for the gear, yes the 35 is an excellent lens, with practice the zone focussing required can give excellent results. The only caveat is that for dramatic water shots the 35mm perspective is a bit stale, most water photos are done at very close range with very wide lenses <24mm to give a more dramatic perspective of the surfer and wave together.
As for the long lens route, at least a 300mm is needed, 400 is better and 500 and 600 is better still, but with a 300 and a willingness to get your feet wet you can do it, with morning light at your back getting a good shutter speed with a slower lens is not a problem, and with 400 speed color print film its not an issue, so finding a decent 300mm f4 or 5.6 is pretty easy ( I just saw a lovely 300mm 5.6 Minolta being practically given away at my local shop). 400 and above gets pricey quick but increases your chances for getting closer to the action, but sometimes showing more of the wave and the relationship of the surfer to the wave is pleasing and popular for the surfer, which leads me to the next point.
All surfers are enamored of their own image, and even getting a half decent blurry shot of them on a decent wave will, without question, give them unimaginable joy looking at. I know this for a fact, being a professional photographer and a long time surfer, each and every frame I've ever had taken of me I treasure even if its pretty crappy. I've often asked other surfers, friends and family to shoot with my gear (after I set it up) just so I'd have Something, some image of me riding waves. SO, showing up a the beach with a camera can make you a very popular person! If you think you got something good, when they exit the water have them give you a name an number or email and by giving them a print or charging them 2-5$ for a print will find you more than a few friends! Over here in Hawaii (relocated 20+ years ago from California) there are a few shooters who post up a popular spots with digital gear and either a long lens or top notch water gear and they have big web sites listing when and where they were during good swells, and surfer's scan hundreds of images looking to see if the shooter got that one wave, and when they do they'll purchase either prints or digital files. Some shooters do very very well doing this BTW, the average surfer compared to the pro's hardly get a chance at a good shot so shooters charge some decent money per image for this.
I'd also suggest looking at good surf photography to get a feel for what's out there. The mainstream magazines are pretty formulaic, but Surfer's Journal is an excellent one and they showcase innovative and often subtle photography that is shot with sometimes accessible gear, more of an overview of the wave like I mentioned.
Above all, have fun and be safe especially doing the water images, let the surfers know if you are shooting with a not so wide angle if you do the Nikonos route, they often see a photographer and think they need to get really close for the shot (which is needed for <24mm) so will actually aim at you which can be dangerous at times. Working with surfers you know increased the comfort and trust level in this regards.