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Riviera 51 Enclosed Flybridge (Not in Production)

Brief Summary

We think that a 50’ convertible is an ideal size and type boat for most any activity offshore: cruising, fishing, entertaining, diving, and just hanging out with the family. And she’s just big enough to use as a waterfront summer cottage. There are about 50’ production convertibles made by major builders, but none have more significant options than the Riviera 51 Convertible.


Length Overall 58' 2'' / 17.73 m
Beam 16' 2''
4.93 m
Dry Weight 48,060 lbs.
21,800 kgs.
Draft 4' 6''
1.38 m
Deadrise/Transom N/A
Max Headroom N/A
Bridge Clearance N/A
Fuel Capacity 978 gal.
3,700 L
Water Capacity 227 gal.
860 L

Engine Options

Tested Engine Currently no test numbers
Std. Power Not Available
Opt. Power Not Available

Captain's Report

Riviera 51 Convertible

The Riviera 51 convertible has more significant versions than any boat in class: two engines or three, pod drives or conventional shafts, enclosed or open.

The Mission

The mission of the Riviera 51 Convertible is to appeal to both ardent sports fishermen and veteran cruising people. By offering a wide number of configurations Riviera hopes to appeal to the broadest possible audience with its 51 foot convertible. The emphasis of the boat is on economical operation and above average performance in a sea-kindly hull.

Riviera 51 Convertible

In the tropics there is nothing like an open convertible to take advantage of gin-clear waters for fishing, diving, swimming and just enjoying life.

Some Back Story

For 30 years the Australian–based Riviera has been building large powerboats and has gained a good reputation all over the world for functionality, reliability, and good sea-keeping abilities. And while we would not consider Riviera a “value” brand, the fact is that it builds a very good boat for prices considerably less than the gold-plated names.
Today the company builds boats in five different categories with 27 models ranging from 36 feet 85 feet. This makes Riviera the largest boat builder in Australia and one of the largest in the world. The brand’s owners are notorious for being remarkably loyal in a day and age when there are many options. This brand affinity is one of the reasons that the company has been able to successfully bring out more new and larger models than any other builder in its category the last several years.

Evolution of the 51

Over the years Riviera has had the opportunity to go back and improve on several models and the 51 is an example of just such a boat. The new model is called the Series II, and Riviera has taken all the lessons learned in the Mark I version as well as ideas that were incorporated in other models and built them in to the new series. The result is not only a boat for all seasons, but one for almost any buyer seriously looking at this size and type of boat.
Among all of the 50 foot convertibles that are on the market, Riviera probably offers a greater variety of significant options of any builder in the world. Let's take a look at those rather remarkable options – –

Riviera 51 Convertible

Note the how the cowling of the flying bridge extends forward of the main cabin. This is an important design aspect of the Riviera 51 Enclosed Flybridge from a visual standpoint. We would paint a black mask across the front of the boat to break up the while fiberglass.

Open or closed flying bridge

Of the eight or so production convertibles currently on the market in this size range we can think of no other company that offers as standard equipment both a flying bridge that is fully enclosed or completely open. Not surprisingly the open model came first and today it is equipped with a standard hardtop resting on attractive stainless steel supports. This is intended to appeal to keen bluewater anglers as well as cruising folks who plan on spending most of their time in the tropics or in warm weather.
The enclosed bridge version is primarily intended for cruising people, however it can also be used by avid sports fishermen thanks to a rear mounted helm on the flying bridge. Essentially, the cockpit in the two boats is the same. Obviously in this category of boat the builder will be happy to put on the optional fishing equipment that may be required by anglers. Conversely., Riviera will happily add optional seating to the cockpit for cruising folks to make this area more entertainment friendly.

Enclosed bridge

It is important to note that the helm on the enclosed flying bridge model is forward. Riviera calls this a “European" helm for some reason, but we consider it just good design sense and have seen it on “American” boats since the 1960s. When cruising in inclement weather it is important for the helmsman to have good visibility forward. By placing the helm close to the forward windshield Riviera has maximized the visibility for the helmsman. Placement of defoggers here, and the pantograph windshield wipers will make visibility much better than through the isinglass used on the open version.

Riviera 51 Convertible

The enclosed flying bridge on the Riviera 51 Convertible incorporates at least seven functions: 1) helm forward, 2)navigator/companion seat, 3) lounge seating with settee, 4) spiral enclosed staircase, 5) aft control station for fighting fish and docking, 6) wet bar, 7) aft “balcony” for viewing cockpit action.

Riviera 51 Convertible

The “open” flying bridge has almost as many functions as the one above. Note that there is more guest seating in this layout and more people can sit around the table. Access to the bridge is through the aft hatch on the port side.

Entertaining on the bridge

When entertaining on the flying bridge underway it is important that the guests are behind the helmsman. Most conventionally laid-out flying bridges on convertibles of this size place the guests seating in front of the helmsman so that he can see the cockpit when fishing. While this is a fine layout for fishing, it is problematical when piloting a boat with a full load of guests on the flying bridge. At night we consider it particularly hazardous as the helmsman tries to see through the people (who invariably will stand and move around) as well as see through isinglass which may be reflecting light or dripping with rain water.

Riviera 51 Convertible

The enclosed flying bridge has lots of advantages. Note the seating at the lower left in the photo which is a bench seat facing aft to watch the action in the cockpit. Also note the handholds on the centerline of the overhead, a signature feature of Riviera boats.

Inside spiral staircase.

The enclosed version of the 51 convertible has the advantage of a interior spiral staircase leading from the main salon to the flying bridge. We like the spiral staircase because it is easier to ascend than a more vertical ladder arrangement, such as the one that you see on many boats in this category, and the open version of this 51. We particularly like the spiral staircase because in a rough seaway there is plenty to hang on to and to lean against both ascending and descending. A spiral staircase also takes up less room than a set of straight stairs.
The downside of the spiral staircase in the interior is that it takes up room that could otherwise be utilized for seating or other amenities. By contrast, the open fly bridge version of the Riviera 51 convertible has a more conventional ladder arrangement leading from the cockpit over the bait prep center to the aft overhang of the flying bridge. Riviera has canted the ladder as much as possible after clearing the bait prep counter, which is better than a more vertical ladder that we have seen on some boats in class.

Riviera 51 Convertible

Four people can comfortably eat at the table on the bridge of the open version. Add two folding chairs and make that six people. The wet bar is aft under the green water bottle. Note the handholds on the overhead above the helm, aft. We think Riviera has done a good job of engineering the visually unobtrusive ss supports for the hardtop.

Riviera 51 Convertible

On the open flying bridge model the helm is all the way aft so that the skipper and manage the boat when big game is hooked up. It is also easy to back into a slip from this position.

Open version.

Because the helm and access point are pushed all the way back to the aft end of the flying bridge more space on this deck is opened up for seating forward than is possible on the enclosed flying bridge model. On the other hand, the enclosed version has two steering locations on the flying bridge, as well as a wet bar and bench seating on the aft overhang of the bridge.

Triple or twin engines.

The Riviera 51 Convertible is the only such boat on the market that comes in both twin-engine and triple-engine versions. In fact the triple-engine model has a completely different hull bottom than does the twin-engine version. The twin-engine 51 Convertible SII comes standard with twin 715-hp diesels driving through conventional straight shafts.

Riviera 51 Convertible

In case you are wondering, this owner/operator who is putting a wrench to a turbo (for some odd reason) is on his knees in the twin-engine model of the 51. Riviera has lowered the profile of the boat as much as possible at the expense of engine room head room, something that is now done by most builders of convertibles.

The triple-engine

version has IPS 600 435-hp Volvo Penta diesel engines. Because these engines are placed under the cockpit and not forward as in the inboard model, Riviera is able to move the main fuel tank forward as well as to install an optional crew cabin amidships. By having the fuel tank forward it means that boat trim is affected minimally as fuel is burned off during the day. It has the added damage of being a good sound barrier between the master stateroom and the engines aft.
The 3 engine pod drive IPS version has a total horsepower of 1305 versus the 1430-hp in the standard twin engine installation. Because the triple-engine IPS model utilizes pod drives and has 125 fewer horses, it is significantly more fuel efficient at virtually all cruising speeds. This not only saves fuel and money, but it also extends the range of the triple-engine version of the 51 significantly.
The engines in the triple IPS version can be accessed from both the crew quarters and with an electrically actuated device that raises the cockpit sole for complete access to all sides of the engines.
Volvo Penta also has a “Sportsfishing mode” for its IPS installation which means that avid anglers will be able to back down with alacrity and follow the bobbing and weaving of even the most energetic of billfish offshore. That nimbleness, together with the added crew quarter option, and the extended range, could make all the difference for a big game anger when trying to decide between two engines or three.

Riviera 51 Convertible

The hull of the Riviera 51 was completely redesigned to take full advantage of the triple IPS drive system. There is a 15-degree deadrise at the transom. Note the hard chines which add stability and help the boat get on plane.

The twin engine

51 model comes standard with a bow thruster which makes docking and maneuvering almost as easy with this boat as with the joystick. With the inboard version the engines are placed in the conventional location underneath the salon. There is ample storage space under the cockpit in the lazzerette.
Access to the engines is through a hatch in the bait prep console. There is full standing head room in the entrance and then “bent over: head room between the twin engines. Reported performance data is published below.

Engines under the cockpit or salon

Along with selecting twin engines or IPS triple pod drive comes perhaps one of the most distinguishing characteristics of all separating the Riviera from other boats in class: engine placement. Usually consumers have no choice. There are advantages and disadvantages to both options as far as placement goes.

Riviera 51 Convertible

In the IPS model the engines are placed under the cockpit sole. This frees up the conventional engine room space under the salon for other uses. In the drawing above the main fuel tank is places abaft the master stateroom and crew quarters are also nestled in.

Having storage in the lazzerette within easy access for storage under the cockpit sole is a tradition in boating. That’s where virtually everything is stored from mops and buckets, to fenders and lines, bicycles, engine oil and most everything else.

Riviera 51 Convertible

With the IPS triples

under the cockpit sole a number of benefits are opened up. First, all of that room under the salon where the engines used to be is now fair game. Rivera has moved the primary fuel tank there which acts as a sound buffer between the master stateroom and the engines room aft. Further, there is now a huge about of space either for storage or for a crew cabin complete with head. Take your pick, or install a little of both.
Access is handy through a clever hatch in the bait prep console. For many people these will be even better than storing things under the cockpit deck.

Riviera 51 Convertible

This is the main deck and accommodations drawing for the enclosed flying bridge model. Note the spiral staircase on the starboard side of the salon.

Riviera 51 Convertible

In the open flying bridge version access to the bridge is moved into the cockpit which frees up room in the salon for a larger settee and an unencumbered entertainment center.

Rigged for rough water

As anyone who has fished off the Great Barrier reef during black marlin season knows the sea conditions on the East Coast of Australia can be arduous. With 5000 nautical miles of Pacific Ocean piling up on the continental shelf of Australia, even on relative mild days the seas can be 16 feet or so a mile or two off the reef. These are the kind of conditions that the Riviera 52 is designed for.
A close inspection of the 51 convertible will reveal that there are handholds virtually everywhere on the boat to aid passengers and crew moving about. Not only are they on the overheads both in the salon and on the overhead in the enclosed flying bridge, but they are also on the hard top of the open version. All stairways have plenty of railings and just about everywhere one looks there is a place to grab on.
The exception to all of this is the galley. Here, there are only minimal fiddles on the Corian counter, no sea rails on the two-burner stove, and no handholds. Go figure.

Riviera 51 Convertible

The VIP stateroom forward has easy access port and starboard and two large hanging lockers. The bow flare is used for valuable stowage.

Riviera 51 Convertible

The Riviera 51 has gas-assist struts to raise the inner-spring mattress of both the VIP and the master queen bed. All boats should be like this one, with stowage under the mattress and in drawers below.

Comparison of Basic Specs

When we compare the Riviera 51 with other boats in class we find that she has the greatest length overall, in large part thanks to its bow pulpit and swim platform. She is a bit on the narrow side at 16'2" (4.92 m), its draft is in about the middle of the class at 4'6" (1.37 m) and her displacement of 48,060 lbs. (21,799 kgs.) is likewise pretty much average for this size convertible. She comes standard with a 17.5 kW generator which is on the large size in class, and should be able to supply enough power for all functions so long as the stove, dishwasher, and dryer are not all run at the same time with the A/C on.
All boats in this class seem to have three staterooms with two heads. We’d say that the room in the staterooms is as good as any boat in class despite the boat’s relatively narrow beam on deck.

Riviera 51 Convertible

Riviera has staged this settee opposite the galley with three plates but we think four people can comfortably eat here. This settee is actually bigger than on some other convertibles five feet longer made by other builders.

Key Features

The salon of the 51 convertible in both the enclosed flying bridge and open flying bridge versions is relatively spacious compared to other boats in class, primarily because Riviera has cleverly pushed the port side galley slightly forward and utilizes the companionway passageway. We think this is a good trade-off.
In the open version 4 people are able to comfortably sit at the settee opposite the galley. In the enclosed flying bridge version the settee is almost as large.

Riviera 51 Convertible

By pushing the galley to port and forward, Riviera has picked up room to make both the settee and the salon lounge sofa larger. Note the tow-burner stovetop and absence of adequate fiddles, hand holds, and sea rails. Refers and freezers are in the pull-out drawers.


The galley is one short step down and has a synthetic teak and holly sole. It features a dishwasher, below counter reefer and reef freezer drawers, and a two burner stove top. The microwave convection oven is forward at the entrance to the companionway going below.

Riviera 51 Convertible

Looking forward in the salon of the Riviera 51. Note the wet bar under the spiral staircase at the right and the hand holds on the centerline of the overhead.

Riviera 51 Convertible

With the push of a button the salon sofa extends into a double bed. Now the 51 sleeps eight people.


The lounge seating in the salon is as large as any in this size range and features upholstery made of premium leather or Alcatara. Consumers can have their choice of a wood work in either American cherry or teak.
There is what Riviera calls a stainless steel “awning window" aft which opens onto the cockpit. This is a reliable way of getting the outside in during balmy conditions and we imagine that sports fishermen might also like it for improved communications with the cockpit. There is rod storage concealed in the overhead of the salon.

Riviera 51 Convertible

The master stateroom is on the starboard side of the boat. While it does not have a portlight, it does have a hatch in the overhead.


Below the layout is pretty standard with the master on the starboard side and a guest cabin on the port side. The large VIP is forward as usual. The guest cabin has a Pullman arrangement which opens up this cabin when only one person is sleeping there. There is a washer/dryer combo in the passageway. The VIP cabin has two large hanging lockers, while the master has only one. Both heads have relatively large stall showers for this size vessel.

Riviera 51 Convertible

The Riviera 51 has a conventional bait prep console complete with sink and freezer. The livewell is in the transom.


The Riviera 51 convertible has a traditional cockpit, by which we mean there is no mezzanine seating at the bulkhead. Rather, there is the conventional bait prep station with sink, freezer, and counter. It must be remembered that anglers in Australia, particularly along the Great Barrier Reef, still use live bait. For that reason bait prep is essential.


We have not tested the Riviera 51 Convertible in any of its versions. On its website Riviera presents a number of different performance tables connected to both versions of the boat. It is unclear from the data presented whether or not the test numbers are for the enclosed flying bridge or open version, or both. Further, as is usual in testing boats of this size, fuel loads and weather conditions vary from test to test. So there is not an ideal apples-to-apples comparison of the performance of the twin vs. the triple engine installations.

Riviera 51 Convertible

It is hard to believe that three engines are more fuel-efficient that two, but it is true. Horsepower and pod drives make all of the difference.

With that caveat, the data presented on the Riviera website suggests that the boat has a WOT top speed of between 30 knots and 33 knots depending on its power configuration and load. Data reported for the boat powered by twin 835 hp MTU series 60 diesels at 2000 rpm was 24.4 knots burning 60 gph for a range of 358 nautical miles. It is reported at 1850 rpm the boat traveled 21.2 knots burning 48.9 gph getting 382 nautical miles of range.
Taking the least advantageous performance numbers for the triple IPS 600 set-up, Riviera states that at 3100 rpm the boat traveled 25.8 knots burning 46.2 gph, getting a range of 419 nautical miles. It is reported that at 2500 rpm the boat traveled 18.1 knots, burned 29.6 gph and had an endurance of 460 nautical miles with a 10% fuel reserve.

Riviera 51 Convertible

The port side guest stateroom has an upper Pullman berth. Hide the stuffed animals and stow the Pullman and the cabin is opened up.

Since we have not tested the boat ourselves we do not feel comfortable placing too much emphasis on this data, particularly since one set of numbers is presented both for the open version and the enclosed flybridge version of the boat. However, the important take-away from this data in general is that the triple IPS 600 installation is significantly more fuel-efficient than is the twin-engine installation using conventional drives.
The data suggests that the triple engine installation is about 30% more fuel-efficient when traveling in the mid-20 knot range. This is consistent with what has discovered with its own testing comparing nearly identical hulls powered by twin diesels vs. twin and triple IPS installations.


With so many choices in the 51 offered by Riviera it is little wonder that buyers are often perplexed as to which combination to select. Each has its own advantages and disadvantages. Regular readers of know that we are not only fans of convertibles as cruising boats, but we also think that the enclosed flying bridge is the way to go. With the addition of isinglass on the aft side, and with full air conditioning and heating provided, this makes the flying bridge and all-weather all-season venue.

Riviera 51 Convertible

The enclosed flying bridge model with the triple IPS 600 system. Note the straight keel and the absence of running strakes. The deadrise at the transom is 15-degrees and the boat has hard chines.

There's no doubt that the flying bridge is a wonderful place to entertain and guests certainly like to spend their time there. Enclosing it simply assures that everyone will maximize their enjoyment from the boat.
Big game anglers who use the convertible primarily for offshore fishing will understandably prefer to have the open version in most cases. This makes good sense because the full helm is at the aft end of the flying bridge, the addition of a tuna tower is far more easily accomplished, and anglers need to be in the open air so that all of their senses can be attuned to the clues as to where bill fish might be lurking.

Riviera 51 Convertible

This open flying version of the Riviera 51 Convertible has the conventional straight-shaft propulsion system. Note that the hull has a pronounces keel, running strakes forward, and pockets for the props.

As to which engine combination and drive system to select, to us it's a matter of initial cost vs. operating expense for those owners who need only modest range. Obviously, the Volvo Penta-powered convertible with the triple IPS, joystick and “Sportfishing mode” will be far more docile when a big game fish is hooked up. But no matter which version the boater might select, in our opinion none of them will be a mistake.