Hello, If a boat has a hydraulic swim platform, and let's say a 15 foot beam. What would be a max size and weight for a tender ? My hope is an 11 or 12 foot AB with a total weight of 550Lbs to 600 Lbs. I'm picturing it on chocks while underway. Could someone go larger? The area I am in is one where parking and then exploring by tender is common.
Recently ordered a 12’ Walker Bay LT with 40hp for 15’ 10” beam. Verify the width of platform allows safe room to walk on platform during launch, most often with prop tipped up. Length of platform should allow for beam of tender. Verify lift platform lift capacity vs. the boat, motor, full fuel, battery, etc, plus the weight of a person that will stand on the platform when launching. It all adds up. Check with OEM of tender and yacht on dimensions and capacity. Good luck.
You need to measure the size of the platform which will always be less than the beam of the boat. Remember beam is measured at the widest point and usually that s amidship with the hull tapering at the stern. Also, with the motor tilted up your 12’ dinghy will become closer to 14’. if the dinghy is too big, it will be a pita when docking as it may hit pilings or docks having room to walk on the platform is a non issue in most cases as you can handle the dinghy from the boat itself. You don’t have to be on the platform as long the boat has a section of fixed platform.
Depending on the boat it’s going on, weight will be as big of an issue as size. When we first installed the freedom lift, I tried a friend’s zodiac 340 that weighed close to 900 lbs. it made the boat a little tender in a beam sea, especially at slow speeds. We opted for the Walker Bay Generation 11 LTE (just order 600lbs wet) and love it.
A 12' dink is about 15' with an OB tilted up but it can work with the motor towards the gate, but that's also putting the highest concentration of weight on that side. Another alternative is a jet drive. It'll allow you a bigger boat in a smaller space. I'd also recommend putting your anticipated weight on your swim platform and bringing her up on plane to see how it reacts. I remember one client who put a wave runner on his 46 Sundancer . It barely got on plane.
You need to contact the manufacturer regarding the weight capacity. I've seen some yachts where the outboard extends beyond the platform, but wouldn't recommend it. A jet RIB will get you a bigger boat on the same width platform because you don't have the outboard that sticks out. I would recommend staying inside the width of the platform itself, which you'll need to measure.
Thanks for the replies.. Ab makes a really light weight 11' but is pretty plain. Seems like a sporty 12 foot can be found at 430 lbs plus motor and fuel. That will still be 600 lbs In many cases I would tow the tender. The waters here are mostly protected. The jet boat is an interesting idea, I didn't think about how more space efficient they are. They are however heavy ..
Had a 35' Cigartte and a 25' Waler on the fold-down gate, got a bit of slap but nothing to worry about. Oh, engineered by some British and Germen students.
I have a 50 ft Viking Sport Cruiser flybridge with a 15 ft beam. We carry an 11 ft 6 in Achilles with a 30 hp Tohatsu and a Euro helm. I chose this set up as I wanted the biggest RIB with maximum inside capacity at the lightest weight. The dinghy is perfect, reaches over 30 mph solo and carries 6 comfortable. It is stored on the swim platform with a davit and the width is no problem, the outboard is most of the way down with the lower unit and prop just hang off the swim platform but not outside the profile of the hull. I think it weighs around 500 lbs total and this does have a small but noticeable effect on the big boat performance.