Dinghy lift

[Our Place]

Hi everyone, we just purchased a 2000 506 MY in August. We have a 12’ Highfield center console dinghy with a 40hp it weighs 650lbs, we want to put it on a lift on the swim platform. We had it on a lift on our previous boat 2002 400 Sea Ray Sedan Bridge. Has anyone put a lift on their boat? Any suggestions?

[Viper]

Congrats and welcome aboard.

What kind of lift are you considering? SeaWeed, TNT, FreedomLift come to mind though I'm not crazy about the SeaWeed. Personally I like the FreedomLift for that class of lifts. Are you looking for a manual or powered lift, or a crane? Do you want the dinghy to rest on or over the swim platform or behind it?

Installing a FreedomLift for example is pretty straight forward though time consuming, and accessibility is everything. The power supply system will depend on what you currently have though I recommend a dedicated battery bank with it's own shore power charging and a means to charge off the alternators. Don't do anything until you've confirmed that the swim platform is structurally sound. I have a customer with a 506 that wants a TNT or FreedomLift but needs some very expensive swim platform repairs before he can do anything. The FreedomLift will bolt up to the transom under the platform but considering the distance from there to the end of the swim platform, it may require additional support to the platform which adds a level of complexity to the install.

Wait for the boat show, I know there's usually some lift OEMs there. That way you can get a few ideas all in one place. FreedomLift is usually around one of the isles before the dinghy section. If you tell them what you have, they may already know exactly what you need for your particular model and can answer other questions you may have.

[bud37]

Welcome to the forum, nice boat.

What did you use on the Ray ? Any fairly heavy dinks ( your 650 +) added to platforms seem to result in deformed platforms over some time (as noticed checking out boats over the years ) not to mention the possibility of severe damage should you get caught in some ugly weather with following seas.

Contact Carver and see what they say as far as platform load and transom load. My self, the dink on the roof or bow would be my choice....gets the 1000# off the stern, assuming dinghy and hydraulic lift total estimated weight.

Another choice to check out, might be, Atkins and Hoyle...Canadian company out of around Belleville I think, nice people.

Hopefully someone with such a rig can chime in.....Good luck with your new boat.

[Our Place]

Thank you for your replies, we had a Bluwater Lift on our Sea Ray with our dinghy. We have that lift still, not sure if we should be putting it on the swim platform. The swim platform has some moisture issues that we will be getting repaired this winter. We will contact Carver for recommendations as you mentioned and we will be looking at the Boat Show. Thanks again.

[Tireless]

Our Place;

I searched high and low for a davit system that would carry a centre console dinghy on the swim platform of our boat. Everyone has an opinion on what is best for them or there boat type and I agree with Viper that a hydraulic system, either a hydraulic platform or a lift like a Freedom lift is superior to most. I guess it boils down to cost and what you are prepared to put into the system $. I looked at the freedom lift at the boat show and it was going to run me $40,000 plus install and I was not sure if it would mount properly on my boat due to how far the edge of the swim platform is from my transom, due to the cockpit.

I ended up purchasing and installing a Sea Weed System, Tender Rollers, made by anchor welding in Cambridge, for my centre console dinghy. I have used it one season now and I think it's the cats aft. They are very good quality, made from 316 Stainless, holding the dinghy up and out of the water. There are different models and they are designed to hold what weight you plan on carrying and the type of boat you have. Mine is designed to hold 800 + LBS, and my current dinghy is a 12' Highfield, with a 30 HP, weighing in at 530 LBS. (aluminum hull). It has a power wench and I have it hardwired to my house battery directly. I plug and unplug it when I am using it and the plug is conveniently storage in the storage locker.

This is a side mounting system that takes about 1-2 minutes to load/off load my dinghy. They are very popular here and in the US because the are made of 316 stainless, very durable and can withstand the salt water, unlike the Bluwater that is powder coated aluminum. I went with the Sea Weed over the Bluwater, but they do have the same mounting principals. I was fortunate enough to find a used Sea Weed on kijiji that was designed for a 12' dinghy and was installed on a boat like mine, 2006 Carver 44 CMY. Big savings for me and it was in perfect condition. Brand new I figure it would have cost $10,000 CDN.

After having my swim platform examined by a fiberglass guy for stability, I installed it myself using a 6 mm poly template I made from the previous boats installation. There is more to this than just drilling holes for bolts and backing plates. I oversized all the holes and filled with epoxy prior to drilling the required holes for bolts. This was done to prevent water intrusion into the balsa core in the swim platform. I also beefed it up by using a two large 1/4" thick marine aluminum plates under the three points of contact under each section, instead of the recommended fender washers behind the individual bolts. If you would like more info on the install please let me know.

I am very pleased with this system and at this early stage I have had no issues. Rudy at Sea Weed was great to deal with, even with this previously owned system. Check out their web site at www.seaweedmarine.com. This was also the best option for me as I only have 18" of swim platform to work with due to the rear storage box. Unless it was extended off my platform I would not be able to carry my dinghy in this manner. I was also not be able to use a Hurley or a Dinghy Caddy system due to my restricted space.

Pics attached. Good luck with your purchase and if you have questions please let me know.

Greg

[Viper]

Greg, make sure you secure the dinghy to the vessel and not just the davit system. I've had a few Sea Weed units fail under load (break) that resulted in the dinghies falling off underway unbeknownst to the operator and only discovered once they were quite a distance away. Having said that, if you secure it too tight to the vessel, it will likely not clear the platform and do some serious damage until the vessel comes to a stop. The dinghy should be secured such that it remains in place on the davit and is allowed to clear the swim platform and be towed for a while until it's discovered that it has broken away should the davit fail.

[Tireless]

Viper, when I am on plane, I secure the bow and stern of the dinghy to the vessel with lines, as you can see in the first pic, in the event it does come off for what ever reason. Water is a powerful force. It is secured on the system with the wench hook at the bow and two ratchet straps on the stern to the catcher. I am interested to know what the weak point of the system is in your experience, for obvious reasons. I have never heard of the system breaking. Is it the welds themselves or the joints. The system was beefed up with 2" square 316 stainless tube in lieu of the normal 1 1/2" at the request of the previous owner. I could never imagine the system breaking under load until your comment. The previous owner had a 12', 750 LB dinghy on there for 4 years with no issue. Mine is 530 Lbs.

What you don't see in the picture are the 4 large support struts that are mounted from the system to the boat. I just realized that the picture was taken before I installed them. These also add a significant amount of support for the system, so the weight of the dinghy is not just on the top of the platform. When I tie the lanyards to the dinghy, I will ensure that the dinghy clears the platform if the dinghy were to come off, as per your comment The dinghy sits off the back of the boat when it is stored as the system is extended out 24 inches.

I was advised by Rudy at Sea Weed that if the dinghy were to come off for any reason, then the wench strap will hold onto the bow and it will fall into a tow position.

[Viper]

The bottom joint of the front arm failed on two units, when that happens, the winch on its own doesn't do anything to secure the dinghy. On one of those applications, the installation had 4 heavy duty SS supports bolted to the unit and the transom so it was as sturdy as you can get it. I was pretty surprised when I saw that that particular unit failed. I've also had to deal with hinged arms breaking away when the adjustable hinge assemblies snapped. This is their achilles heel IMO based on what I've seen.

I'm sure there are many in operation that have been trouble free but I have to go by my personal experience and it's not like I've been around hundreds of them so in comparison, the failure rate seems high from my perspective. High loads due to rough water and running conditions seems to be the biggest contributing factor IMO. One must consider that the weight of the dingy is only part of the equation, the amount of load/force exerted on the assembly while underway in certain conditions can far exceed the dinghy's weight. It wouldn't surprise me to find a 530 lb dinghy exert close to or exceed the 800 lb rating under the right conditions. I suspect subjecting these joints to constant jolts and cycles of high loads is what causes them to fail and as long as you are aware of that it may help reduce the possibility of that happening.

Rudy's a great guy by the way.

[bud37]

Source of the post High loads due to rough water and running conditions seems to be the biggest contributing factor IMO. One must consider that the weight of the dingy is only part of the equation, the amount of load/force exerted on the assembly while underway in certain conditions can far exceed the dinghy's weight. It wouldn't surprise me to find a 530 lb dinghy exert close to or exceed the 800 lb rating under the right conditions. I suspect subjecting these joints to constant jolts and cycles of high loads is what causes them to fail and as long as you are aware of that it may help reduce the possibility of that happening.

I agree , I really don't know anything about Seaweed lifts but I do know that point loading is an important consideration in any of these projects, as I touched on earlier. A 600lb load on a 2' lever is now effectively 1200lbs and so on, and as Viper states the extra forces of vibration and jostling do nothing but add.

Just something to consider, when discussing the engineering of these units with the people that make them.

[Viper]

I agree Bud. Ratings are typically for a static state or calm conditions where external influences are minimal. Add a little chop for a few hours and you have to start worrying about metal fatigue and joint/weld failures. The bigger the chop, the more exaggerated the load over and above the weight of the dinghy. That applies to all brands. I'm sure they test in extreme conditions during r&d but we all know it won't produce the same results as a few years of real world conditions.

The potential loads involved brings me back to ensuring that what you're bolting any system to is structurally sound and beefed up to accommodate the additional loads that will now be placed on the existing structure. Loads exerted on the lift will be transferred to the mounting structure and in some cases multiplied, and if not installed properly will result in future issues with the platform or transom. It's a pretty common issue and by the time one realizes there's a structural problem, it's already a very costly repair.