Jim,

You have several options.  First, you will have to go to an electrical supply house - NOT a big box store - in your area, because the pedestal breakers you want ARE NOT 5 mA trip GFCI breakers.  In the electrical Industry, what you want are called "Equipment Protective Device" (EPD) breakers, and they have a setpoint of 30mA.  They are made for commercial/industrial applications.

EPDs are made by Carling and Eaton.  Eaton manufactures under several brand names, like Square D and Cutler-Hammer.  Carling probably does the same thing.  Carling makes the ELCI breakers that are sold for boat applications under the name "Bluesea Systems."  "ELCI" is the term used on boats; why they couldn't stay with "EPD," to be consistent, is something I'll leave to the village special squad on speculation and guesswork.

Find out what kind of main service disconnect panel you have in you home.  That should be on a label inside the door of the service panel.  You will need to buy an EPD that is compatible with the attachment style of the current service panel.  There are breakers made under many house names.  But whatever the name, it will have to fit the panel you have.  If the panel doesn't have a name on it, take a breaker from the panel with you when you go to the electrical supply house.  The counter man can match the style you need.

What you are going to do is identify the breaker that supplies the pedestal on the dock, and change that breaker to an EPD in the main service panel.  The EPD will have a test button, just like GFCI breakers.  That button will be yellow or international orange.  That's how you know it's 30mA instead of 5mA.  If the dock pedestal is served by a sub-panel in the house, that's OK too.  It's the same procedure: identify the existing breaker and change it out with the new.  Very simple DIY task that can be done safely without turning power to the whole panel off, but that's your call based on your comfort level.

Keep the old breaker handy, because if the boat trips the new EPD, you will probably need to put the old one back in order to debug the boat.

EPDs are expensive.  A 50A (double-pole) breaker at a big box store is probably $30.  A 50A double-pole GFCI breaker will be $60.  The EPD will be in the $400+ range.  Why?  Because they can and besides, the testing specs are different.  Oh, well...  it's a "one-time and done" expense...

Hope this helps!

Jim

Peg and Jim Healy, living aboard Sanctuary
http://gilwellbear.wordpress.com
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436

Jim Healy... thanks for the great and informative info... I finally head back from the vendor that made my power pedestal... for about $270 bucks they will ship me a "marine" GFCI breaker...  I had learned about the difference between a "marine" style GFCI (30 milliamp trip) versus "home" style (6 milliamp trip).  I read about a guy who used a "home" style on his dock...  He said that if his boat would not trip the 6 milliamp one at his dock, he would for sure be ok at marinas with the 30 milliamp trip breakers...

Any thoughts on that?

Also Home Depot sells (the 6 milliamp trip home GFCIs)

GE 50 Amp Double Pole Ground Fault Breaker with Self-Test $109

and 

Square D Homeline 50 Amp 2-Pole GFCI Circuit Breaker $99

On the Home Depot web site, someone said to not use a 2-pole GFCI but rather to use a double pole GFCI... I thought they were the same thing?

Jim Gano

Jim Healy.... I forgot to mention this.  On the side of my house is an electrical box with a Square D breaker labeled by the electrician who built my house and it says "Boat Dock"...  the breaker is a single switch breaker (not a double switch) that is 100 amps..

Jim Gano