Most people use a 50 ft.

 

Get 50' and coil any excess neatly out of the way. A too-short cord is useless.

 

Like was mentioned above, buy the 50'. A cord that's even 6" too short might as well be a mile short.

 

50 is best. Eventually you’ll also want to go to other marinas and it helps

 

I have both in my travel bag. Many marinas we stay at as transients have poor power systems and have more slips than power pedestals. This approach gives you 80' if you needed it.

I have a second set of 50' cables permanently attached to my slip so I never have to remove them.

 

I have a 50 footers too. I coil the excess around the base of the power pedestal at my slip. They also get locked to dock as as not to grow legs (again). I have twin 30 amp power so 2 cables on the dock seen below. A little messier than usual in this pic.

 

Or get two 25’.... easier to deal with if you mostly use 25’

 

With all extension cords the underlying rule is to use the shortest one possible, so a modular approach may be a best of all worlds solution. Yes, power cords are made with gauges of wire meant to reduce line losses, but it still happens and increases loads on the electrical equipment like AC pumps and compressor motors.

Like Brad, we have two power plugs, so we carry two 25’ and four 50’, plus a 50 amp to 30 amp splitter. In the two years we’ve owned this boat, all of these have been out of the storage locker at the same time on more than one occasion.

 

Where are you traveling?

Are you returning to the same "home" slip all the time? Or are you taking trips, staying at transient slips?

 

Mass, NH and Maine. A lot of the places we go to in Maine do not have dedicated transient slips, so a lot of times I end up having to use two different pedestals. Although the worst case we ran into was in Provincetown last summer. There they use big multi boat pedestals (8-10 outlets). The pedestal on our section was completely dead and the place was packed, so there were four - five boats (including us) with cables going everywhere.

 

If the only place you ever anticipate using the shore power is at your dock, will 25' work based on the placement of the shorepower post compared to your boat inlet? Otherwise, get a 50' and as noted, just coil the remaining.

Can you clarify what model you have? Sea Ray wasn't even using the "SDX" moniker in 2006. Do you have a 2006? Is it a Select, a Sundeck or a Sundancer? Reason I ask is that if you have a bowrider, the shore power is likely only used for a battery charger and an outlet or two and it may be unlikely that you are ever going to be in another slip (possible, though).

 

Thank you for the input, it is a Sundeck. I've corrected my profile. The power connection is solely for the battery charger.

 

Power cords are bulky, take up a lot of room.

If you are traveling... get the 50.

 

270 Sundeck - ah, that makes more sense.

OK, so along the lines of what I mentioned above, if you don't anticipate ever using another slip, don't buy more than you need. It only takes a day or two to get a cord - if you can't get down to the docks now to measure, just wait till you can. It's not like you need it right away, anyways, since it's just for a battery charger.