I hope this may be of help
If you own a older rib that has subsiquently got a Ce mark for the same model as yours,It is realy cheap to get your boat CE marked as the costs are on a one off basis for all hulls that are manufactured out of the same mould.Any alterations you make may need approval and the cost is aproximatley maybe £400 for a full re inspection from a CE specialist.
The company who makes the boats may want more money from you as there aproximate costs for a cat B boat are inspections are in the region of 2k for all the models and they may not want the liability.
If you own a cat C boat and you want to go Cat B then you can do the tecknical file yourself,and get some specialist advice and read rcd specifications,as it is possible but the costs will be 1.5k+
If you own a none ce marked boat but it is a work boat then the manufacturer may help if it is subsequently the model is CE marked bye the builder,as it will have stability and can be applied retrospectivly providing the existing manufacturer plays ball etc.
If you own a protortype and subsequently you want cat B ce mark then for that model,then you could get it ce marked retrospectively providing the said manufacturer has ce marked that model of boat.alternativley you could put the boat through CE marking yourself,aprox cost 2k+.
If you own a none ce marked boat that your sure will go offshore in then you can pay for it to be Ce marking yourself,the costs are aprox 2k+for cat B a few changes that you may need to make it comply.imho its unlikley a boat less than 6 mtr will get Cat B imho.
So its not all doom and gloom exept for those that bought a big old work boat Rib and want to comply with todays RCD calculations for cat B offshore. If it passes stability and downflooding withought to much modification then you are ok- 2k.
The important guide for which you can maybe do nothing about is freeboard 4inch to be safe catB or 6inch for cat A,when fully loaded.with fuel and all people.
You may need to have less people on board to achieve this standard.Im not sure weather there are any twin diesls ribs less than 9 mtrs long that can achieve this! so be carefull.If they appear a bargain and are listed as a work boat and you want to run as a recreational boat long term for the future.
They may get an exemption ? but I cant say they will,so check them out first.
If this has happend I would suggest you speak to your trading standardes people or RCD consultants or live in the hope that the insurance companys dont swich on and make thing difficult in the future should you want to sell.This may well not happen.So this is not the end of the world but you need be aware of it.
I have no crystal ball and dont want to worry people but the implications of what is happening out there in conformatie world are quite concerning to say the least.
Maybe nobody will do anything as there will be a crossover of tecknology, but I am speaking from the stand point of what could happen and what things one should bear in mind for the future if you own a rib or are thinking of buying a new one and the 2nd hand value and the future is important to you.
The future is out of our control.
Your safest option at the present time is to have a CAT B boat rcd inspected and certified.IMHO for offshore use.And ask for the GZ curves before making a decision.
So Good luck and I hope there is something in what I have said that may be of help to existing rib owners and future ones.