I am working on a seastead design.  It has lots of solar power.  It has 4 big columns that go down into the water 
at 45 degrees making for a small waterline area and lots of drag for any pitch/roll type motion.
However, it does not make for a fat vessel.   Realisticly it takes a lot of force to
even move at slow speeds like 1 MPH.  So we want lare slow RPM propellers to give us effecient
thrust at these slow speeds.  Probably the seastead is around 30,000 lbs total and
has like 22,000 install watts of solar so we hope that 2,000 watts is enough for at least
0.5 MPH continuous movement.  

Part of the advantage of our seastead is it looks like it could be less than 1/3rd the cost 
of a yacht of comparable space.  We have decided to try to keep costs down so rather
not spend too much on the thrusters.

I am looking for a "low speed submersible mixer" that with 2500 mm diameter propeller (or larger)
and power like 1 to 5 kw.   These are sometimes called "banana propellers" and "flowmakers".
A similar thing is "Sea Water Aerator Pusher" that might be good.
Does using submersible mixers seem like a good plan or is there some other way to get similar
large propellers running on electric motors?

Plan is to use 2 thrusters spaced wide apart so we can use differential thrust for stearing.
So we would like 2 units to give us enough thrust to go maybe 1 MPH.

I have collected links to some submersible mixers with large propellers below.
I would like it to be ok to use in salt water.
Are any of these able to run at variable power levels?  
I guess this is called, variable frequency drives (VFDs).
What sort of price are these really?  I think often the price on this
made-in-china.com site are not accurate.  Is there any other sources to
confirm what prices really are? 

Can you find any other links to ones that might be better than these?

Do these come with controllers or are those seperate purchases?
What do variable frequency/power level controllers cost?

Which of these looks best for me?  What would the price be?

European

https://ptm-mixer.com/products/phantom-2500/
      2500 mm - maybe $13,000

https://www.xylem.com/en-uk/products--services/mixing-mixing-equipment/single-speed-mixers/4410-low-speed-mixer/
https://www.xylem.com/en-us/products--services/mixing-mixing-equipment/adaptive-mixers/4320-low-speed-mixer/
Flygt 4410 (or 4430) Series
      Best thrust/kw   but probably most expensive.

Landia
      https://www.landia.co.uk/Files/Images/landia/dataark/Landia_DataSheet_POPL-I.pdf
      2300 mm   at 1.5, 2, 4 kw
      Does not show thrust in specs which seems really bad

Wilo
      https://wilo.com/us/en_us/Products/en/products-expertise/wilo-emu-tr-216-tr-e-326?t=4#range_productlist

Sulzer
      https://www.sulzer.com/en/shared/products/flow-booster-type-abs-xsb-900-to-2750
      2.75 meters


Japanese
      https://www.shinmaywa.co.jp/english/products/pump/introduction/sm_sme/sm-vrtn.html
      https://www.mrm-shinmaywa.com/filesdirectserver/itp1/z_itp_12042022f9ii/originalz-z721968334010.pdf
          2.5 meters 
          3200 newtons   - (720 lbs)
          Is stainless and ok for seawater
          2–3.2 kW

 

Chinese:

https://www.vivamixer.com/submersible-mixer/submersible-mixer-wastewater-treatment.html
     VIVAMIX VML2500/3kW  - 2090 Newtons  (470 lbs) - $2,000 in cast iron, more in stainless but not sure how much more
     Can get 220 volt 3 phase 60 hz
   Henan Eco Environmental Protection Equipment Co.,Ltd
   www.vivamixer.com/www.ecowatertechs.com
   Email: luna@ecowatertechs.com
   WhatsApp:+86 13522525054


https://henaneco.en.made-in-china.com/product/NZLTJhwrCCAU/China-High-Thrust-Submersible-Mixer-for-Large-Volume-Lagoons-and-Biological-Wastewater-Processes.html?pv_id=1jhanagq25f0&faw_id=1jhanatqj7c6&bv_id=1jhanatqqc2d&pbv_id=1jhanadof56b
          VML-2500   have 3 kw 2500 mm version  but says cast iron 


https://lingchunhuanbao.en.made-in-china.com/product/LFxaKerEghfd/China-Qjb-Type-Low-Speed-Liquid-Agitating-or-Mixing-Submersible-Mixer-for-Water-Purification.html?pv_id=1jhannbd9e2d&faw_id=1jhannlr06a2&bv_id=1jhannlr9774&pbv_id=1jhann9264e4


https://lanshenpumps.en.made-in-china.com/product/eorQAjxvahVt/China-Submersible-Centrifugal-Slow-Speed-Propeller-Mixer-QJB-1-5kw-7-5kw.html?pv_id=1jhannbd9e2d&faw_id=1jhaodp9t97b&bv_id=1jhaodpa50aa&pbv_id=1jhann9264e4
    QJB3/4-2500/2-29B   - 3 kw 2500 mm   1960 newton   220 kg


https://chinalanling.en.made-in-china.com/product/fTnYEdIuOKkX/China-Submersible-Mixer-Qdt-Low-Speed-Flow-Pusher-Hydrolysis-Acidification-Tank-Sewage-Pool-Blade-Mixing-Propeller-Propeller-Manufacturer.html?pv_id=1jhanagq25f0&faw_id=1jhaov8ac911&bv_id=1jhaov8ag0f8&pbv_id=1jhanadof56b

     QDT5.5/4-2500/2-47   5.5 kw    11.3    2500 mm    47 rpm  3840 newton    310      kg
                                                                863 lbs


https://qiankunhb.en.made-in-china.com/product/ixVrWqadVTpm/China-Qk-Qjb-Low-Speed-Submersible-Mixer-with-Impeller-Diameter-of-2500mm.html?pv_id=1jhaphkvsa73&faw_id=1jhapi041ae8&bv_id=1jhapi04be4b&pbv_id=1jhaphito324
    QJB4/4-2500/2-42P 	4 kw 	9.2 amp 	2500 mm 	42 rpm 	210 kg



Can you find any "marine Aquaculture pushers" that are over 400 lbs push?