Seafury Surface Drives

The Duchessa may be the nearest to the Opera in the line today since the Opera was a flybridge model but then it lacks the speed that the open and coupe models have. That's our problem with the flybridge models in general is that the lack of speed and the lack of the range we'd like. We're happy with the 40 knots, 36 kt. cruise of the opens and coupes but the 32 knot, 28 cruise of the bridge models just isn't Riva enough. One of our best friends bought a Rivale a few months ago.

The new 76 is 37 knot, 32 cruise but it's very futuristic.

Absolutely not the lightest. So far they have adhered to their tradition and character, whether one sees that as good or bad. The two new models are a bit different but still looks like same conservative construction. With the deserved criticism of Ferretti on the Bertram fiasco (although honestly the mistake was the purchase initially), Ferretti to this point has kept the individuality of the different lines quite well. When we tested a Pershing, it was so uniquely different from Riva, as it should be. Even Riva's ultra modern designs as you call some of their newer models, don't seem out of character with the rest. Now our Riva's are old designs.

We will wait and see, Suetonius.

HTM09,

It seems to me below 20 knots there are several choices... all of them submerged drive systems, including: props, variable pitch props, pods, and counter rotating props

Between 20 and 30 knots is about the same but one might consider in addition to the above water jet and surface drive is most time is on the upper limit.

Between 30 and 40 knots perhaps in smaller boats pods are still possible. But really only three choices are available variable pitch props, surface drive and water jet... if one is operating on the lower end then really the variable pitch prop is the better choice. But if operation is primarily on the high end the water jet and surface drive come into there own.

The problem with water jets is they take up lots of internal volume or length which places the engines forward so this is only a real option on larger boats... or boats where internal volume is not primary concern day boats. I suppose maybe 80 ft. is the transition point where water jets are possible.

Actually, what might be interesting is twin surface drives powered by diesel as primary source and a centerline water jet with a turbine... for sprints. The turbine starts and warms quickly but can be used for that supercharge when desired.

HTM09
I have seen that thing personally... and it was both funny, as I was watching on shore at a distance... but if I had been anywhere near it on the boat... or it was near my boat or God forbid moored near it... I would have been very much less than happy. But is is a fun hobby boat for those involved and operating it.

Moonen has built several boats with the servo gear drive... both Nilo and Phoebe are for sale. But they are limited to 26 knots and are larger than you like... and are heavier and semi-planing. C-32 Cat powered.

Actually the servo gear is very similar to the Levi-drive subject of this thread... except it is underwater and under the boat hull at the extreme aft end. But it has builtin semi-tunnels in the hull. I think any builder could install it but in a fiberglass hull they would have to make a couple tunnel bump inserts for the mold. Of course an aluminum hull can be anything you want.

Rich could most definitely meet those numbers with conventional shaft drive! As you know, interior accommodations of a SF are meager compared to the types HTM09 is looking at but I'm sure he (or other custom builders ) could adapt their proven hull forms to different superstructures.

Talk about water over the transom, here's a pic I was sent of one of mine last year down in the Dominican Republic. By the level I figured it's right at 20,000 pounds of water. They went on to release the fish they were fighting but still gives me shudders looking at it!

My humblest apologies Carl (or whichever mod caught the too large picture size), I wasn't paying attention and mistook file size for the pixel width. In between coats of clear on a Hatteras transom and maybe the respirator wasn't tight enough!

I totally agree it was needless or excessive backing down Capt J! Worst part was the alcohol abuse, two cans floating over the transom!

Hope this pic is sized properly.

I see discussions on Seafury Drives. I have been using Seafury drives on my 53' and they are great and have had no maintence problems. The service from Seafury has be en good although I have not had any need for anything. About 800 hrs on the drives. Call is you need info. NUMBER REMOVED

I have run a pair of arnesons ASD 12 for 21 years in fresh water and just had to have the seals redone. Only cost around $7,000.00. Very reliable if you change the gear oil each season and keep them clean.

The problem I see with the Sea fury drives is there is nothing to protect the props in front of them. The fin is on the rear and it is too late if you are moving forward! Props tend to be very expensive.

53 aluminum Diaship with 1000 hp MTU engines ZF gears Rolla ss 30 in cleaver props which cruised at 43 knots until this last Labor Day when I had a governor failure and blew up my port engine which has been the subject of the technical forum "Bosch. Governor failure". Cruise on the Great Lakes not salt water!