Regatta Networks is a great choice!
You can use the service as a stand alone regatta site just like the A cats do with the compete-at product or you can integrate it into your club web site like Rock Hall YC does.
http://www.rockhallyachtclub.org/regatta.htmas the season goes... each box will be filled in with the link and allow you to link to regatta networks for the entry form that you can design.
There are about 6 companies that provide regatta services.
We have almost 10 years of experience in using online registration and our policy evolved to publish the regatta price and then add on the service charge for the service when you go to pay. People have no problems paying the surcharge for ticketmaster ... and no problem with the regatta fee.
Just like the ball game... If you have bought the ticket... you show up at the ball game... no matter what the weather... unless it's canceled you won't get a refund.
Also.. you have no problem paying more at the door for the privilege of deciding to race at the last minute. 20 bucks seems to be about the right amount to encourage people to sign up by Thursday night of a Saturday regatta.
Unfortunately, this deadline does not help much with T shirts.... the printers really need more time to not charge you a rush fee. Cascading deadlines... with the No T shirt for you after xx date are easily set up in any of the systems.
Food order deadlines vary... a YC needs to usually order food by Tuesday at Noon for delivery on Friday. Burgers and Beer on the other hand can be purchased on Friday with the info collected by Thursday night.