shore power question

Unless someone added a ton of stuff to your boat, I see no reason why it would possibly need 2 50amp cords running to it. You are using a Y now but in theory you could plug into two 50 amp outlets on the dock.

I can almost guarantee it left the factory with two 30amp outlets. Probably still has original breakers on each leg of 30-40 amps.

Somewhere in the past mine was converted from 2 30's to a single 50. Done behind the outlets in the cockpit. I have never had an issue running everything on a single 50. There is a benefit to running two 30's - easier to find power at docks, cords are much cheaper\lighter, and more overall power.

I am no expert at electrical, but maybe someone in the past had 50 amp outlets available and swapped them out for the 30's. It could be as easy as putting back the 30 outlets to the A&B legs or combining to one of your existing. You really need to trace everything on the boat and understand what you have there today.

I also have a 1981 42'.

read the power outlets on the boat carefully. What you probably have is 2 50A 125v outlets.

Your Y adapter is a 50A 250v.

On mine, i have two dongles that each convert the 50A 125v to 30A 125v plug. I then have two 30A 125v shore power cords that run to the Y adapter which converts the two 30A 125v's to a single 50A 250v.

I would think that there is potentially a Y adapter that accept your 50A 125v's from the boat and convert to a single 50A 250v and then you could run a single 50A 250v shore power cord to the dock. But i haven't researched it, so i don't know for sure.

Hope this helps.

You need to look at the pin configuration on the plugs but it indeed sounds like you have 125v-50 amps inlets on the boat side and use a Y to combine them to the 125/250-50 amp not he dock pedestal

The 125-50 has one 125v hot, 1 neutral and a ground.
The 125/250-50 has 2 125 hots, 1 neutral and a ground, both hots are on opposing phases to produce 250v between the hots.

125-50 was popular back the but pretty rare these days, at most marina you will find 125/30 or 125/250-50

In theory you should be able to replace the twin inlets with a single 125/250-50 by connecting each 125 hots to the new inlet hots, and then connect both neutral wires to the single neutral on the new inlets and same with the ground

Check the size of the wiring on the shore cord. The 30 amp plugs are notorious for burning up if you try to start 2 ac units at a time. Quite a few got changed out to 50 amp plugs. Most boats run the ac units on one bank and the remainder of the house service on the other bank.

Use the Y adaptor at the power pole on the ships service entrance. Pick up a 240v/50a cable. Plug your new 4 conductor cable into the Y and the other end into the dock power tower. Simple and expensive one cable..
Your 120v/50a cables still use #6 wire but it will only have 3 conductors (No red lead).
To get rid of the Y all together, replace one of the 120v/50a service entrance receptacles with a 240v/50a, rewire both your old service entrance receptacles (3 wire) to this one new 240v (4 wire) receptacle.

Our old Bert had one 120v/50a AND one 240v/50a services. 120 line for lights and chargers. 240 line for the ACs and stove/oven.

A lot of the older boats around here still use the setup you have. It is hard to find a marina with a 120v/50a service any more.

This is correct, except they're inlets. 2 - 50 amp 125v coming into the boat. Easiest way, as suggested is to have the 2 - 50 amp 125v to 1 - 50 amp 250v splitter at the inlets connected to a single 50 amp 250v cord to the dock. Twin 50 amp 125's on the dock end do not exist anymore, if ever.

Rare, but they do exist. Watch Hill. Fire Island has it, and the number one spot at the dock in Waterford NY has it because one of the canal boats has that power and uses that spot when there.

Pascale's advice to check the plugs is spot on, because it could be 50/125's (most likely with that boat), 50/250 if it draws more than 50 amps and you're able to split you load (least likely and that "Y" would defeat its purpose, or even twin 30 amps going into (1) 50 amp at the pedestal (quite possible).

50amps at 250 volts= 100 amps at 125 volts.

Swapping the 2- 125V 50AMP inlets to 1 250v/50amp inlet and wiring it correctly and using 1 250v/50amp cord would be easier.....but then you're looking at $1000 in parts (the cord and the inlet plug,waterproof cover) You might also have to change the diverter switch (gen to shore).

But at the same token, you could easily overload a 30amp shorepower cord using a 250v/50amp to 2-30amp Y and 30 amp cords.

Confused with that..

Weather it's a 240/50 or a 120/50, each 120Vac lead has a 50 amp breaker.
Since the 240/50 has two 120Vac leads, there are 2 50a (Gang) breakers in the dock box or power pole. You're not getting 100 amps from that power pole thru either of these connects.
Total amps on board for use?? the O P has 100 A (on two legs) available either way.

50 amp cords use #6 wire. 30 a cords use #10.
30 A hardware is much cheaper and everywhere. Brand new boats are still delivered with dual 30 a service connects.
This spring/summer already have been more perfect examples. 30 a cords are frying everywhere already. Got 2 calls last weekend where the boat lost power and the marina stated power pole good.

Old, Fried 30 a cables both times.
One call on a newer power Cat.

The other call,,, down the far dock. Not many people go down the far dock. Reminds me of a haunted house, everyday, in daylight, with un-shaven monsters about (the guys could use a shave also).

One of the customers commented (on the far dock); the ends keep corroding, so he unplugs them, plugs them back in the other Y lead, gives them that cleaning twist. "Sometimes you have to twist them a couple of times for them to self clean".
He demonstrated this in front of me. His Air system was still on trying to restart. I could hear the arcing in the plug,, in his hands.

Some people you just can not reason with or help. I just told him the cleaning stations in the equipment were worn out and he needed new cords and a new Y adaptor. He agreed stating the cords were many years old and probably due.

I tip toed away,, very, very quickly.

Luckily, I usually don't get calls down the far (snail-boters) dock that often.
It's a story every time


If it's powering more than a charger and a light, stay away from any 30 a junk.
You (and I) will sleep safer at night.

Exactly, each 125volt lead has a 50 amp breaker, yet everyone is using a 50' 125volt cord rated for 30amps, not 50amps.

There were (still is) 50', 120Vac cords rated at 50a. 3 conductor with #6 wire. I understood that was what the OP had. I really hope not the 30 amp cords. There could be one heck of a BBQ if so.

Now, The far dock people use that 50a to twin 30A Y connects. Yep, They have cook outs often.

There is but it is costly, Here is what you would need to do. 1. But a 50' or so 50amp/250volt shorepower cord. 2. Install a 250v 50amp boatside recepticle with cover. Wire the boat's shorepower wires to the 250 volt 50amp boatside plug making sure that each of the boat's 125 volt hot wires are on a seperate leg of the 250volt receptacle. Install A proper 250volt 50amp breaker on the boatside. If you're not a good electrician, I would hire a marine electrician to perform the work. Then based upon your panel, you may need to install a 250volt 50amp, off, generator selector switch. Without knowing what your boat has, it's hard to determine, but you may only need the cord and the boatside receptacle and may be able to utilize your existing 50amp/125volt breakers for each leg but I don't believe so.