Anything is worth trying but a few things to consider:
A chap in my sailing group recently bought a H14 with cut down rudders. The seller lived and sailed in shallow water channels with lots of sand bars.
It's not speed which has been compromised but steering ability and comfort. The steering is there but less responsive, always pulling and in no way as smooth as it should be.
Also here in Australia we have an old cat named the 14ft Caper Cat. Great little cats which were released with 'spade' shaped rudders suited for those in shallow waters and just easy to beach without the hassle and worry. Over the years these rudders were retro fitted with must longer (standard looking) rudders to add performance/steering etc.
If you have anything like this in the US you should give them a try. A pics here for you: http://bluepeteraustralia.files.wordpress.com/2013/01/jan12-080.jpg