I have made many suits, but I do a lot of the work with a serger. I don't think they are hard at all.

My machine is a 37 year old Singer.
Ginny

It's been(seems like a million)years, but I made a suit once on a Singer(made in the 70's)that just had a few different stretch and zig-zag stitches. I don't think the fabric was any more difficult than most knits. Just be sure to use a ball-point needle.

Thanks for the information. I haven't worked on knits for 30 years so this could prove to be a challenge.

Ginny

I have used spandex to make myself blouses and dresses. With most of it I had no trouble if using a ball-point needle. Once in a while I hit a spandex fabric that made the needle skip stitches. Someone told me that in that case, I should cut some long thin strips of tissue (or any other kind of paper that is easy to tear off when done) and stitch through them as I sew. It could be a bit tricky, as you need to very slightly stretch a knit while machine sewing it, but it does stop the skipping.

Oh hey - not to discourage anyone from sewing on the Sewing Forum, but have you looked @ the swimsuit 'tankini' tops @ Target? They have the kind w/ a flared panel - apron-style. I have several I wear w/ black swim shorts & I love 'em - they're about $20 online, but less, I think in-store....

Here is a link that might be useful: Tankinis