I think you've fallen fallen victim to some trademark urban legends. Let me try to explain some of these misconceptions in simple terms.
A trademark doesn't need to be registered. Even if you searched every trademark database in the world it would not prove that no one had a trademark.
You can't change or add a letter or two and get around a trademark. Infringement is gauged by the likelihood that someone would confuse the words you are using with the trademarked words. You are NOT safe simply by using words that are not an “exact match”
In this case we have a company called Ocean Finance and Mortgages Limited. They have a registered trademark “Ocean Finance”. They use the domain names: oceanfinance.co.uk, oceanmortgages.co.uk, and oceanloans.co.uk.
Now if someone, somewhere out there in the big world where they have oceans and loans, decided to set up a company and use a similar domain name that would probably be fine. But when their next door neighbour decides to register a similar name it starts to look fishy. And when that neighbour talks about selling the name to them it becomes a pretty clear case of cybersquatting.
It's not a big deal, just don't try to sell the name to them, and don't try to pass yourself off as them. If you find the name has no other value when it comes time to renew let it drop. Worst case your out ten bucks, but a lot wiser.