Jet Ski Dolly as Beach Trailer for SUPER SPORT 13

A conversation among Whalers
GChel
Posts: 3
Joined: Fri Jan 14, 2022 9:47 am

Jet Ski Dolly as Beach Trailer for SUPER SPORT 13

Postby GChel » Fri Jan 14, 2022 9:59 am

Can a jet ski dolly be used as a trailer to launch and recover a c.1985 SUPER SPORT 13 on a beach?

BACKSTORY: We are close to beach but not close to a ramp. Launching off the beach would be super easy for us.

jimh
Posts: 11673
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: Jet Ski Dolly as Beach Trailer for SUPER SPORT 13

Postby jimh » Fri Jan 14, 2022 10:30 am

The term "dolly" suggests propulsion by hand, not by attached vehicle.

Can a SUPER SPORT 13 sitting a dolly be pulled out of the water, uphill, on a sand beach by hand by one person?

A lot depends on the dolly, the slope at the beach, the tires and the sand, and your strength.

How would you transport the SUPER SPORT 13 on its "dolly" between your residence and the beach?

A SUPER SPORT 13 hull has a length of 13-feet, a beam of 5-feet 5-inches. and hull weight would be around 400-lbs, not including an outboard engine, fuel tank, fuel aboard, and other accessories. For an all-up weight I would expect at least 500-lbs, if not more.

A small jet ski like a SeaDoo SPARK has a length of 9-feet 2-inches, a beam of 3-feet 11-inches, and weighs around 420-lbs.

GChel
Posts: 3
Joined: Fri Jan 14, 2022 9:47 am

Re: Jet Ski Dolly as Beach Trailer for SUPER SPORT 13

Postby GChel » Fri Jan 14, 2022 1:13 pm

dolly_.jpg
Fig. 1. The "dolly" that is the topic of this discussion.
dolly_.jpg (11.37 KiB) Viewed 1665 times


I would tow [the dolly] down to beach from our house using a golf cart. The beach is soft sand. [The dolly would need to be moved] by hand about 75-feet [up or down a] small incline. [The work involved would] not terrible but [the work] would likely be painful.

[The concept of using a dolly and pulling it by hand may have been] a bad pipe dream.

hauptjm
Posts: 45
Joined: Mon Oct 19, 2015 3:26 pm
Location: New Orleans

Re: Jet Ski Dolly as Beach Trailer for SUPER SPORT 13

Postby hauptjm » Fri Jan 14, 2022 3:02 pm

Off loading is one thing, but getting the hull back onto that dolly is another. Judging from those tires, the dolly is likely to float which would make getting back onto the dolly almost impossible.

GChel
Posts: 3
Joined: Fri Jan 14, 2022 9:47 am

Re: Jet Ski Dolly as Beach Trailer for SUPER SPORT 13

Postby GChel » Tue Jan 18, 2022 10:22 am

hauptjm wrote:Off loading is one thing, but getting the hull back onto that dolly is another. Judging from those tires, the dolly is likely to float which would make getting back onto the dolly almost impossible.

It was a bad idea. Thanks for confirming.

jimh
Posts: 11673
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: Jet Ski Dolly as Beach Trailer for SUPER SPORT 13

Postby jimh » Tue Jan 18, 2022 5:52 pm

DOLLY in this discussion means "bunk trailer with four giant balloon tires."

HAUPTJM--excellent point about the buoyancy of those four giant balloon tires. I doubt you could even get the boat off the "dolly", let along get it back on the dolly.

A further problem: will the hull at rest on the trailer--err, the dolly--bunks clear the tires? It does not appear they would.

The concept of an all-bunk trailer when launching is simple: the trailer is backed down an incline into the water until the stern of the boat becomes buoyant. The buoyant force removes a very large amount of the total weight that remains bearing on the trailer bunks. The boat can be pushed off the bunks easily. This paradigm is corrupted if the trailer itself has its own buoyant force and does not remain on the sea bottom during launching or loading.

jimh
Posts: 11673
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: Jet Ski Dolly as Beach Trailer for SUPER SPORT 13

Postby jimh » Tue Jan 18, 2022 6:06 pm

If you really want a beach trailer for a 13-footer, I suggest this design:

  • use plastic and very low height wheels, with wide tread
  • use four-or-more axles so the weight on any one tire is reduced to the point where the tire won't sink into the sand
  • the trailer should be made from aluminum to reduce weight
  • the handle should be able to be attached at either end of the trailer frame, and it should have a Y-shape at the trailer attachment so it will fit around the outboard engine gear case
  • the trailer is pulled into the water to launch from the stern, and pulled out of the water from the bow.