We have a keel trailer  trogen 5x  10x ratio winch.
 A 18v 1.5 ah drill that pulls a 5.5m boat with great and 80/100l fuel on up a steep ramp faster than a solid fit guy can wind it up. Battery is good for 2 1/2 retrieves.

 Go for a wide drum....and with min amount has 2 turns on drum and just hook on at end of trailer. of delema rope with a drop forged hook (has flat sides)

 Reason for this.. the smaller the diameter of the drum, and increases when rope layer go on, means more effort, thu faster IF maintain same winding speed all the way.
The effort between 1st and 2nd lay is ball park 1/2 more effort.. 3rd layer doubles.

Another hint.. for any winch.. when 1st get it, put the rope out the front side.. chock the trailer wheels.. hook to the car with hand brake on a little to create good loading. Then wind the rope on under load , feeding across the drum.
 You will find the rope will feed correctly by its self when loading the boat in the future.

 Never lube the winch bushes with a petroleum based lube..  not crc or similar.. inox non petroleum based lube fine.
 Petroleum based lubes attack the bushes then they bind up, making big noise and jumpy, hard to just pull out.
The bushes are easy to replace if lay everything out on a bench when dismantle. and abut $2:50 each.
 Normally only the main drum bushes will fix the issue.

Got a feeling this maybe your issue?

Thanks Steps, great advice. Just purchased the same winch and 7m of rope, hope it will take that length. Will set it up as you say.
The frame was in good Nick, only drum rusty as hell. The two speed will be a life saver.
Cheers.

Like this?
https://seadesign.co.nz/

Geeze.. $33  for an old long 2nd hand  16mm socket with couple slots cut in it and a 3/8" adapter cut down to fit the drill.

The weight and design of boat and trailer will dictate the specification, size and torque of battery drill required to retrieve your boat.

So they have no idea or recommend what size drill, what ratio winch for what weight of boat. Or able to recommend if wide or narrow drum.. wire, braid or web 'rope'
 Get any of these wrong and doesnt work.

I put a scale between the winch hook and the boat, and watched when someone pulled up the boat and took the time taken.. anything over 1 min was not acceptable.
I then calcuated the force required to being the boat up in 1 minute.
Then with some difficulty found out how much force a battery ( mains power tools easy to find) drill has, and at what loads batteries will cut out at when loaded and reach given cut out temps.
 Then calculate the speed of the drill, what ratio required (and rem the ratio, and load changes as the winch drum fills) to bring the boat up in 1 min or under... on a keel trailer.

Then came proof of concept, on a quiet week day at the ramp,near full tide because that when the ramp is very steep.
1st pull scarred the $%^& out of me...I had calculated with the drill speed on 1.. did not realise in the excitement it was on speed 2... Damn that boat came up real fast, got to just before meter full up and battery and/or drill cut out kicked in just in time.
 This was an unexpected  surprise thu.
 Then pushed boat back out , did the next pull 5 min later (let drill and/or battery cool off (they where only just warm to touch) on speed 1 .. not 100% sure the 1.5AH battery had the storage capacity.
 Anyway it pulled up about 5 sec under the 1 min
Damn near right on the theoretical calculations
 for a approx 1100kg , 5.5m 1970s sea nymph commander fully loaded including fuel but no ppl.

Proof of concept nailed.. 1st time, no try this try that messing around.

Someone has been watching some very old posts here i think..

$1 2nd hand socket, 50c for adapter , 10 mins time, and if want to get fancy, tack weld the socket to the adapter.
Where has good old Kiwi  number 8 wire stuff gone?

Wonder when my bungy panter will go commercial....
 or my self tied off mooring to pontoons solo launch.. just rool off boat, automatically tied off the pontoons/ wharf, and drive away.
or my quick retrieve light solo lift 800mm no mess,dredge set up, that will have proof of concept , hopefully this weekend.
 Or my $15 moded  $35 dredge its self, already well proven on its 1st proff of concept.
 Then there are other things like my spit, still not upgraded from original proof of concept from around 35 yrs back.

Secret to all this. "work hard at being lazy"  And that is very different from the modern concept of "work smarter not harder"
 Work hard at being lazy one will spend a sunday putting under ground automatic watering system around 20 odd aviaries so dont have to change the water each day...
 Or removing all weed from lawns so only have to cut 1/3 as many times with less catch each yr.
 "Work hard.......at being lazy"
 And not having deep pockets is also a great motivation to build.

Here’s another winch powered by a cordless drill attachment, lots of videos on YouTube with guy’s powering there boat winches with drills

https://winchdrivertools.com/products/icnuts-marine-tool-kit-operates-one-winch-for-boat-trailers

Here a winch designed to be powered by a drill

https://www.topmaq.co.nz/automotive-workshop/vehicle/winches/drill-powered-winch-225kg-avwi2000?gclid=EAIaIQobChMI-fSWhZqB7AIVciCtBh09tQsSEAsYAiABEgIE3fD_BwE

This one’s from 2012 ideas been around for a while so must work pretty well might buy one myself

https://www.thebackshed.com/forum/ViewTopic_mobile.php?FID=11&TID=4990&PID=0&LastEntry=

Great read, esp for those of us with heavy tubs and a steep ramp.
Bought a sea socket last week and used it for the first time on Sunday. Brilliant. Older De Walt drill gave up with 2ft to go so will need to replace that.
Cheers Steps and others.

Most likely the battery as Steps says, but...