Fitting aftermarket spray rails and silent chines to over 80 boats have been big business for Motor Yacht Service Centre, but it has also resulted in 80 delighted owners.
Motor Yacht Service Centre’s Dean Ryder kept hearing from many of his clients about how ‘wet’ their boats were at speed, so he decided to do something about it.
“Traditionally, modern launches are designed quite full in the bow to maximise internal accommodation, so they tend to push a fair bit of water. So, following comments from the owners, I thought we should look at a solution to help alleviate this issue”, says Dean.
Adding spray rails around the stem area is nothing new, and it was common on many boats designed by Don Senior designs over 30 years ago. While the trend is now to have the lifting strakes and spray chines taper away at the bow, Dean’s idea was to maximise this area with an accentuated rail on either side, fitted just below the waterline.
Dean says they start to work around 10-11 knots, and as the boat begins to ‘pop’ the bow, they come up above the waterline and curl the water back down. The faster you go, the more effective they become. Another bonus is that they eliminate most of the spray on your windscreen and break the vortex of mist around the transom.
The first boat to be given the aftermarket spray rails was a 20m flybridge, and according to Dean, the results were outstanding. Now 13 years later and more than 80 boats on, he has tweaked the design to what he says is about as perfect as he can get. They have been fitted to boats from 39ft through to 70ft, and Dean says they would be suitable for even larger vessels.
“Every boat design is a little different, and although the principle is the same, the rails vary in placement, length (3-4m), and the angle of entry is also critical to each boat. It is important to get the angle correct, so you don’t start pushing the bow down in the following sea”, added Dean.
The dimensions of the rails are not something he is prepared to divulge. However, he will say they are constructed of high-density foam, which is shaped and then bonded to the existing hull before it is glassed-over with woven rovings, chop strand mat and polyester resin. After fairing and painting, the new strakes look like part of the original hull design.
“In the case of a production boat, this is something that the factory can’t include, due to the reverse angles would not allow the hull to be released from the mould”, says Dean.
SILENT CHINE
Going hand in hand with the aftermarket spray rails is the addition of silent chines. With the forward area of the existing chine filled in, it is also necessary to add the spray strakes to make up for the reduction in the chine area.
“The wave action or slapping occurs at the intercepting point where the scumline meets the chine and depending on the angle and shape of the chine, we infill an area about around 4.5m long, which also has a slight radius on the outside”, said Dean.
Like the spray rails, these are also constructed of foam and GRP.
Here is what some happy owners had to say about the modifications.:
Greg Martin who had both the spray rails and silent chine modifications to his, 57 Flybridge said “Our slapping is near non-existent due to the filled in chines and that means we can now anchor anywhere and enjoy a good night’s sleep”. Plus, he says that with the spray chines the boat is a very dry ride and handles well.
Craig Roulston had spray rails fitted to his 51 Sport Sedan right from new after
Dean recommended them.
“Having clocked up 250 hours on the boat now I can report no more than a cupful of salt spray over the forward deck in that time. Steaming at 15 knots with 20 plus knots on the beam, the deck remains dry apart from the occasional wisp thrown up”, says Craig.
Brian & Cath Carran say that MYSC spray rails have given utheir 70ft sport sedan dry decks, less salt and a windscreens from the helm. “We would use our wipers only 20% of what we previously did to clear spray.”
“The filling in of the chine has reduced the slap when at anchor considerably, especiall.y in the front cabin. Money well spent!”
So what does it all cost? A pair of spray rails or silent chines vary based on the vessel and therefore, the cost will vary slightly between boats. We would recommend contacting MYSC to see the spray rails for yourself and get a price suited to your vessel. The whole job takes about two weeks.
There are currently six further boats booked into MYSC, Clearwater Cove yard for the aftermarket spray rails and silent chines.
Motor Yacht Service Centre | www.motoryachtservicecentre.co.nz
