700’ Fixed Pier

[Grootsquad]

I recently walked through a job where a 670’ fixed pier has been constructed straight out to where a gazebo/sub panel will be located for a few general outlets and lights. From there will eventually be a floating dock beyond it with possible shore power in the future (brings us to about 700’ straight out from beginning of fixed pier). Before the ramp down to floating dock there is a 90 degree turn to the south and 128’ where will be 8 boat slips/4 fingers on this fixed pier that will not supply shore power, only lifts for dry storage. There will be a new service no more than 20-30’ from fixed pier entrance that will be dedicated for the pier. The lifts will be standard 240v/2p15a. I plan to use Benders Marina Guard control panel and CTs for the 100mA GFPE protection of feeder. My question is sizing on this run. It’s very long obviously to the sub panel and it is straight. 2.5” PVC with several expansion fittings (6-7) and my calculation on 250kcmil has a 7.2 volt drop on voltage that is usually already pretty jacked up around these parts and that’s feeding a 100amp sub panel at minimum. In all reality there will be little neutral current and there will not be eight boat lifts running at the same time. The lighting that leads to gazebo/boats will be solar so no load there only the few outlets/lights at gazebo. I’m thinking I could get away with two 3/0 copper THHWN conductors and a #1 grounded conductor and #6 EGC, but I wanted to see/hear thoughts from anyone that may have been in a similar situation in the past and willing to help! This is for someone’s personal property
Thanks in advance

 

[augie47]

I would lean toward an AL feeder unless you have an unlimited budget. As you stats, the load is limited.
250AL (or #1 Cu) would only be a 5% drop on a 50 amp load which seemingly would cover your situation,

 

[Grootsquad]

I would lean toward an AL feeder unless you have an unlimited budget. As you stats, the load is limited.
250AL (or #1 Cu) would only be a 5% drop on a 50 amp load which seemingly would cover your situation,

Thanks for the input augie. The budget has not been set but I do plan on giving both options. I need to find out if the plan is for shore power at the floating dock or not. If not I could size the voltage drop on a 50amp load and may be more cost effective to run a 2/0 copper Type W cable and eliminate 700’ of PVC/pulling off of four spools