This is my 1st post here... ("Long time listener, first-time caller"). Glad I found this excellent forum!
My wife and I moved to the Benicia, CA area a year ago. I was an avid diver until I totally ruined my ears, and we both love being on the water. With a free public dock to the Delta/SF Bay only 2 miles away (our gateway to the world), I knew a boat was in our future.
So I did a lot of research, started saving my pennies ($5k budget), completed the Calif. Boater's Certification course, and cruized craigslist twice a day for a couple of months. After viewing a dozen-or-so used candidates (most were "rode hard and put away wet", needing too much TLC for me), we found a 1990 Horizon 220 w/Cobra 5.7L for sale by the original owner (who is quite wealthy), near Lake Shasta. He took his family out a couple times a year, and always stored it in a huge 2-story garage (as big as my house!). He babied this boat, and added lots of nice goodies - a Halon fire supression system, electric anchor winch/windlass, fishfinder, depth sounder, bimini & towable covers, etc. The upolstery, carpet, hull, bimini, & towable cover are all nearly perfect - only 140 original hours, and impeccable service records. He was asking $4.5k and we settled on $4.1k.

All-in-all, we did much better with this boat than I'd expected given our meager price-range.
But no deal is perfect -- in his case, the original painted-steel FW tandem trailer is the problem.
The prev. owner boated in the brackish Delta for a couple of seasons before he moved to Shasta, after-which it was fresh-water only. But those trailer-dunks in the brackish Delta water started the inevitable rusting process, which progressed over the following years. At this point there are areas of deep rust on the cross-beams and other critical spots. The steel is 'hella thick so it is not very easy for me to determine the actual structural integrity. All feels solid at-rest, but I doubt we'd have much-if-any warning-signs on the road before a disaster might strike.
After the purchase, we towed it back from Shasta just fine (4 hr drive @ 50mph) during a huge rain/wind storm. 'Probably not a wise move, but it was certainly more stress on the trailer than I'll ever risk again. Since then, I've done one 4-mile round-trip to the local dock for our maiden voyage -- but bad freeway-nightmares have been interrupting my sleep, so she's grounded while I work this out.
Thus my challenge - to find a safe and suitable (and hopefully low-cost) trailer solution. I'd appreciate any comments/advice from this group of 'sages. Here's my thoughts;
1) Initially I'd considered having the trailer repaired, (rusted crossbeams replaced, completely sandblasted and repainted), to maybe add another 5-10 years before the rust gets scarey again. But I'm not sure if that is even possible, and it would have to be significantly less cost than a replacement to make sense ('may also need new brakes, hubs, axles, so that is a big-if).
2) Save my pennies to buy a new aluminum tandem trailer.
Less saltwater worries and the reduced weight would be vey nice for towing.
My main concern here is how well my FW would be supported. I've been reading about the importance of properly positioned bunks, and FW trailer manual makes a point of describing how their trailer bunks are optimally positioned for the exact model of my boat to prevent hull distortion.
Even after a lot of Googling, I'm not finding much specific info about bunk positioning issues on new after-market boat trailers, even on the manuf. websites. Does one need to buy a 'custom-built' trailer for optimally-positioned bunks? If so, what criteria does the manuf. use for that (i don't see any mention of specific models, only boat length and weight). What about "fully adjustable" models like EZ Loader (held together with bolts, not welds)? Or is this a non-issue, and we'll be fine with whatever 'standard' bunk positioning is provided?
Any brand/dealer to consider are very welcome, especially for availability-in/delivery-to the SF Bay area.
3) Save a few less pennies and try to find a used aluminum tandem trailer.
So far, these seem to be few-and-far-between in our area, and are still fairly pricey for used. And I have even more concerns about proper bunk positioning and support of my boat with a used trailer, if that is a legit. concern.
4) Or, buy a new gavanized steel trailer. I'm not sure that the price difference from aluminum is really worth the extra weight, and I have the same concerns about bunk positioning. If I must go 'new', would there be any significant advantage to galv. vs. alum. other than price?
Well, I did not expect my first post to be such a Novella -- I hope it isn't too tedious to read and I look forward to any thoughts/suggestions (or even a gentle dope-slap or two ;o)
Cheers, and 'glad to be aboard!
--RF