We have a Defever 49 and we do love the way the boat handles. She can handle rough seas, only problem was that the admiral and our dogs could not. A Defever 49 does like to rock and roll, so keep that in mind.
Like SeaDog already stated, if you plan to go out at sea you may want to think about either finding one with stabilizers or otherwise be prepared to install them yourself. We had the bilge boards, but they did absolutely nothing, only had a bit of damping effect when we would hit the wake of another boat. But the swell and the waves.......it was rocking and rolling.
Now that we have stabilizers she is stable as a rock and we have been out in 9 Bft with heavy seas, was still stable.
For 2 persons the inside space is more than enough, 4 persons is no problem but we would have to change the interior (remove our recliners and install a U shape settee. The 2 cabins are generous, forward cabin has mattrasses of almost 7', so if you are a taller person.........that space is perfect for you. We have converted the forward cabin and the extra head in storage space since we spend a lot of time on anchor.
The best part of the boat (at least for us) is the sun deck and the fly bridge. Together it is a massive space (sun deck alone is over 250 sqf), so in the summer evenings....that is where you can find us. Access to the fly bridge and sun deck is easy via a 4 (or 5) step stairs in the pilot house.
Engine room is unfortunately not stand up, which is a pity, but still roomy enough to get everywhere with ease.
Lazarette and ER can be reached via a hatch in the cockpit. There is an extra ladder on the bulkhead between ER and master that leads up into the galley, but we never use that one, in fact we closed it off.
Our boat is powered with 2 x FL120 and that gives us a cruising speed of 6.5 kts at 1400 rpm. We could push it up to about 7.5 kts, but the extra fuel burn does not make it worth while. In fact when we shut one engine down, push the other one up to 1600 rpm we do about 5.4 kts. So 1 engine extra only brings us 1 kt in additional speed. In other words, if the weather is calm we always shut down one engine and increase our range.
Bow deck has a portugese bridge and the deck is large enough to create comfortable seating while underway (with good weather) or while on anchor (or in the marina). Can easily sit there with 6 or more persons (if you would want to).
Our boat has a bow- as well as a stern thruster, which means you can bring it into every spot you would like to.
Draught is 5' and props plus rudder are protected by the keel.
Length over the water line is 49', but overall length (swim platform to anchor) is closer to 60 - 65'. Here in Europe that is not a problem since they will charge you for what it says on the registration card. If that is a problem in the US you may want to think about it.
A Defever used to come with metal fuel tanks, but over time they would start to corrode. If that happens and you will need to exchange them..........you are not going to be happy. Basically you have to empty the complete ER, even the engines have to come out. So we were happy that work had already been done. Fuel tanks hold close to 850 gallons and when we run on 1 engine (we have velvet drives) we burn around 2 Gph with a speed of 5.4 kts. That gives us a range of about 1800 nm with 20 % reserve. On 2 engines our range drops to about 1100 nm with 20 % reserve.
Obviously when you need to run the generator that range will go down. That is why we installed a large solar array and lithium bank so we don't need to run the generator at all.
What to check when you find one ?
Check the complete wiring. Our boat was 1979 and although the surveyor said everything was fine we found out that most of the original cables needed to be replaced. So make sure you check that well. There are a lot of cables running in the cabinet on the port side of the master and the cables to the bow thruster and anchor run through the bilge, under the bed in the master (that is also where the water tanks are), so you definitely want to make sure those cables are in good condition.
Check the deck for soggy spots in the deck and leakages around the hatch to the sun deck / fly bridge.
One item we are not so happy with is the way the stern cleats must be reached. Here in the Med we always have to do stern to mooring and getting to the cleats is just not easy. You have to hang overboard to be able to feed the lines through the opening in the hull. No idea who came up with this design, but we will change it this year.
In all we love our boat, but am pretty sure other trawlers will do just as well. For us a Fleming remains our dream boat, but unfortunately far out of our reach.
Hope this back ground info helps a bit.
