Power cords should never be extended in Marina environments.
75 feet 30 amp Marine power cord.
US$154.80
https://megadepot.com/product/marinc...xoCkaEQAvD_BwE
Is each leg of your 50 foot and 25 cord properly rated for a total of 75 feet of length.
The longer the cord the larger the wire size so as to keep voltage drop to proper levels.
For 75 feet, 30 amp 10 gauge, 50 amp 6 gauge
IMHO, it seems like you are being penny wise and dollar, not so smart.
FYI:
http://www.pcmarinesurveys.com/Marin...l%20Safety.pdf
HOW TO
WORK WITH YOUR SLIP HOLDERS TO BEST PROTECT YOUR MARINA
Sources of electrical hazards can be from boats or from a marina’s power
equipment. A marina operator can take precautions and steps to ensure all marina power sources are safe, but a marina operator cannot ensure a boat is free from hazards. While it may seem logical for a marina to require electrical inspections or conduct inspections on boats, there is a great risk of liability in undertaking such actions. One way to avoid liability would be to have a third party, not related to the marina or the boater,
conduct an annual electrical fitness test for slip holders. The slip holder could be required to pay for such a test as a contractual obligation. The test would use either a “pigtail” device with an ELCI installed to detect a fault over a period of time, or a test with a clamp-on meter on a shore cord with all boat systems energized. While customers might balk at an added cost to have this
test performed they can be reminded the test provides a value in knowing a boat’s
electric systems are sound.
Another simpler and free means for a marina operator to help prevent electrical problems from boats is to supply slip holders with a list of best management practices and suggestions on how a boater can best protect a vessel from the risk of fire or leaching stray currents. While providing the list is not as reliable as requiring testing, it may make the most sense for a
particular facility and its customers.
Marina operators should distribute the following responsibility code and onboard
safety message to all customers annually to remind them of the importance of electrical
safety and encourage them to take steps to ensure their boats are safely connected.
Boaters’ Electrical Responsibility Code
PLUGGING IN:
1. Use only shorepower cords and adapters that are in good condition. Common problems include cuts, loose blades, burned ends, or melted plastic around the connections. When in doubt, replace them or have them repaired by an ABYC Certified Marine Electrician.
2. Use the right cord for the right application, 30 amp 110 volt or 50 amp 110/220 volt. Adapters must be approved by the marina management.
3. Purchase and use only products that are “factory assembled” by a recognized manufacturer and have the UL listing mark.
Read and follow the manufacturer’s instructions and warnings. Do not use “homemade” adapters or shorepower cords.
4. Support the shorepower cord adequately to prevent damage during
wind, wave, and tide action. Make sure any locking rings are fully engaged and in good condition.
5. If an appliance has a 3-prong grounded plug, never eliminate the ground pin by either removing it or using an adapter.
If the ground pin is missing or has been modified, discontinue use of the device immediately.
Onboard Safety
1. Know where your main breaker(s) are located on both the boat and the shorepower source.
2. Do not use any plug-in battery chargers that are not UL rated for marine use.
3. When using “straight blade” portable tools or extension cords always ensure these tools are connected to a Ground Fault
Circuit Interrupter (GFCI) protected receptacle.
4. Test any Ground Fault outlets on board monthly and consider converting traditional outlets to Ground Fault.
5. Leave non-essential AC
equipment OFF when not on the boat, this includes water heaters, outlets,
lighting, etc.
6. All electrical installations and
repairs must be performed by an ABYC Certified Marine Electrician or must follow the
ABYC Electrical Standards with the use of products designed for marine use.
7. Do not alter the AC
electrical system in any way