get the impression you’re doing the job on a rather tight budget? fishing boat, crane mounted sheave, clump weight of a second crane? two man operation, dp1 free boating? no HPR?
what sort of search and recovery job you looking at- mass, size?
600m recovery is really not simple using a cheapo rov, especially if you’re going a hook/connect up job to a tugger line (even with a xenon strobe). Also It’ll take you at least 20-30mins to get to depth and in that time, you may drift like a swine (fun without hpr!) even if you use a really heavy clump weight and under an 15mm diam umbilical !
are you looking at using the manip to hold the object recovered or drop the object into a skip?
if it’s a large object, have you thought of marinising a mechanical grab and mounting cheap subsea video cameras/lights on it and then positioning the vessel? do you even need a rov, or can you dump a frame over the target and mount something cheap like a hydrolek within the frame and power up using a cheapo umbilical??
thought of short-term hiring a half-decent spread?? You can hire a seaeye falcon spread from dps for a couple of duckets- they’re based in aberdeen next to seatronics who can also provide you with some decent sensors too. Day rates are around 1/200th of purchase price.
http://www.dynamic-positioning.co.uk/Data%20Sheets/DPS_falcon_DR.pdf
I don’t think they have a manip skid on their stock list at the moment, but I’m sure you’d get a deal somewhere with seaeye direct or build your own tooling skid? fun !!! 😆
Also, this guy has a falcon with a 5 function skid.
http://www.subseavision.co.uk/Standard%20Falcon%20Specifications.pdf
Any of the rental companies can hook you up with things like kongsbergs new portable hipap 410, a half decent collision avoidance sonar? might cut your op-time risk significantly enough!! (cost per day however may be cheap enough that you don’t care?)
If you’re looking at a small rov, purchase is going to be around 30-50k GBP + single function manip – and you’d be getting something old and hard to get spares/technical support for.
Good luck!!