[Ajax_MD]

I wouldn't get hung up on brand names, but you should be prepared.

By "prepared" I mean, you should have a thin, warm, wicking, base layer, then a fleece-like middle layer, then a waterproof top layer.

How you get there, is nobody's business.

You can buy Under Armour knock-offs at Wal-mart.
You can find Columbia knock-off fleece tops practically anywhere.
Wear dad's Grunden's for the top layer.
You can buy rubber rain or muck boots practically anywhere.
For sailing gloves, Atlas gardening gloves that have the palms coated in rubber are cheap and effective.

You can delete the middle layer if the climate is warm and wet.

Just don't expect all the knock-offs and hand-me-downs to last as long or be quite as effective as some of the name brand gear.

 

[Ajax_MD]

Let me clarify a bit:

I suggested the approach that I did, because the OP seemed to indicated that this was a one-time operation. I DID specify that cheap, off-name gear would not last as long or work as well. It just doesn't make sense to pour a lot of money into top name gear for one-time use.

I personally, own and wear Helly-Hansen base-layer skivvies, Columbia fleece and poly-propylene mid-layers, topped with Helly-Hansen coastal bibs and their Tactician's jacket. I did cheap out a bit, and buy BOGS sea boots instead dropping $400 on Dubarry's but they haven't let me down so far.

I sail often, and in poor weather so it was worth every penny.

 

[Ajax_MD]

<snip> It doesn't have to be labeled "Sailing" gear to work. Having the right layers and combinations is really what it's all about for any sport. <snip>

No, it doesn't have to be labeled "sailing" gear, but I've learned that buying quality "kayaking" foul weather clothing costs virtually the same as buying quality "sailing" foul weather clothing.

It's a false economy...