Salt air and stiff sea breezes won't have done much to help your aerial and the cabling.
If you're up on the roof and can check easily then have a look at the end of the cable. So many installs use crappy cable with a aluminium foil shield and thin ally or copper braid just to save a few pennies. With the connection cover missing then salt and water will have got in. You'd be as well replacing the cable as well as the aerial.
The aerials on Tool Station are all crap. Avoid. The ones on
Screwfix are mostly the same except the 28-element Log Periodic. If you have to buy from
Screwfix, then that's the one to get. I can't say it'll be as good as the better quality Logs available, but at £3.75 it's for nothing and hardly a loss if you have to replace it with a decent £12-£15 Log after a year.
Log Periodics have a couple of really big advantages over other aerial types. Firstly, they are a true wide-band aerial, so you'll get the same sort of reception quality no matter what channels your local transmitter uses. That's certainly not the case with other wide-band designs.
Second, the slim profile reduces wind loading on the aerial and mast, and so there's less force on the bracket and whatever it is attached too. If you've ever had to pay the bill for repointing a chimney or had the hassle or redrilling to fit a wall/eves bracket that's worked loose then you'll appreciate the value of this.
Don't buy your cable from either site though. Neither site sells anything decent. There's no spec on the sites nor on the manufacturer's own site. That's poor.
Buy Webro
Webro WF100. For the amount you'll need it won't cost a lot, but it'll give you a stronger signal at the TV and it'll last 3/4/5 years longer too, so the extra few pennies you spent per metre won't have been wasted.
The only extra you'll need apart from plugs (F type) and cable clips is possibly a masthead amplifier.
Houses a long way from the transmitter or in the lea of hills or trees will need some help with reception. An amplifier does that. A Masthead amp does it the best. It gets the signal at its cleanest where it comes direct off the aerial and adds sufficient power to give enough signal at the TV for decent reception. This is different to those set back boosters; they're amplifying a lot of noise with the signal. That's not as useful.
The same site that sells decent cables also sell a range of masthead amps and accessories.
Personally, I'd try the aerial first and see what sort of signal level you get. Look at your TV tuning menu or wherever they've put the Strength (S) and Quality (Q) metering. If you get 80%+ on Quality without the amp then I'd just stick with the aerial & new cable. BTW, Quality is the most important thing. Strength is only important of the metter shows it well below 50%