Simmon's Sea Skiff-lift Tabs

[seamac]

Anyone w/ knowledge of S.S.Skiff ? Saw one 20yrs ago and remember the "hook" built into the bottom ( at transom ). Is this the way to go instead of external tabs ? Representative drawing of S.S. Skiff transom "hook" is also on my "wish" list. I'm finishing 25' flat bottom skiff and interested in possibly using such a technique. Ideas welcome .

 

[PAR]

Hook is an old school trick for a number of different hull forms. It depends on what you need and what will provide you these needs, before any solutions, such as installing a hook, can be offered. Launch your boat, get some experience on it and shake out the bugs, then if you have an issue, some shingles could be attached to develop a hook, if this is what the boat needs.

 

[seamac]

Par

Thanks for the help.

 

[seamac]

Par

Thanks for the help. Will let you know how it goes.

 

[keysdisease]

Install trim tabs

Just install trim tabs. A 25ft boat will have constantly changing loads and operate in a dynamic environment. People move, fuel gets used, fish come aboard, beverages get comsumed and the water can change from flat calm to a real sea.

Trim Tabs will allow you to adjust the boat to optimal trim under all loading and conditions.

Steve

 

[PAR]

As a rule Simmons Sea Skiffs don't need tabs. It's foolish to recommend or install anything that your hull doesn't require. Complete the project, sea trial the boat, then make a decision about what it might or might not need.

 

[keysdisease]

If the loading of the vessel is distributed in such a way as to trim the boat to optimum performance and the loading remains the same and the sea conditions remain optimum for the way the vessel is trimmed and no one moves you would be correct.

There are many things that are not "required." All thats "required" of a powerboat is that it will float and move. Seamac is finishing a 25' skiff and the trim characteristics are unknown. Experimenting with hook or wedges or shingles would after trial and error allow the boat to run well trimmed in a specific range of loading and conditions.

Trim tabs are reliable, inexpensive and allow the vessels trim to be adjusted to a wide range of loading and sea conditions on the fly at the push of a button. They are not "required" but typically are a worthwhile option. They will certainly be more practical than a shingle or wedge.

"Old school" thinking used to be that trim tabs were needed to "fix" bad designs. Try finding any planing or semi displacement boat built in the last 20 years over 25ft without trim tabs. There's a reason almost all have them.

Steve

 

[PAR]

I'm not going to argue the point Steve, but tabs are common in modern craft because of the shapes employed. It's still ridiculous to suggest things the boat might need before trials, particularly if you are not familiar with the design. The Simmons skiff is a well understood and known design. It preformance envelop and it's edges are well defined and tabs aren't necessary.

 

[keysdisease]

I didn't say they were necessary. I said: "They are not "required" but typically are a worthwhile option."I also suggested that they were a more flexible and reasonable option to trial and error with wedges or shingles with additional benefits.

I would also question "but tabs are common in modern craft because of the shapes employed." "Modern craft" employ just about every shape imaginable for a planing or semi displacement hull shape. Trim tabs offer a wide variety of benefits like quicker time to plane, easier planing, the ability to plane at slower speeds, the ability to trim the vessel to on an even keel due to load inbalance or wind and wave conditions and the ability to adjust running attitude to meet conditions.

I don't see how "modern craft because of the shapes employed" fit your opinion unless you define all planing hulls as "modern."

In light of the benefits of trim tabs I don't see how recommending them is either foolish or ridiculous.

Steve

I'm not going to argue the point Steve, but tabs are common in modern craft because of the shapes employed. It's still ridiculous to suggest things the boat might need before trials, particularly if you are not familiar with the design. The Simmons skiff is a well understood and known design. It preformance envelop and it's edges are well defined and tabs aren't necessary.

 

[tom28571]

"Modern" boats tend to be shorter, fatter and beamier than those of old and that means that initial planing is harder to achieve. These factors mean that trim tabs will be more beneficial to new boats than older and lighter weight ones with higher L/B ratios. Still, trim tabs can be of benefit to many older small boats. Whether they have a positive cost/benefit quotient on a Simmons is another question. Simmons skiffs have been running the inlets, near ocean and sounds of this area for decades without such complication. The hook that Simmons settled on for his boats serves very well and with older manual start outboards meant that no battery was needed for day use.

Would a remotely adjustable set of trim tabs work well on a Simmons? Probably they would. As said, adjustment for different conditions would then be possible. However, in all the many Simmons that I have seen, none had tabs and all had his designed hook. Are they ridiculous? I would not go that far but they are unnecessary for the boat to do its job very well.

 

[tabman]

I just helped an owner of a 1954 Simmons Sea Skiff 18 footer spec Trim Tabs for his boat. He gave all the "right" reasons for wanting to add them after owning the boat for a while.

I will get back in touch with him for an update and see if he has installed them yet.

Tom McGow
Bennett Marine

 

[PAR]

I'll add lots of deadrise in comparison to older designs as well to the typical hull attributes that contribute to needing tabs.

My whole point is not adding tabs to a boat that is not completed, hasn't shown a need for tabs historically, particularly in light of how many have been built and successfully operated in wildly varying conditions without them.

 

[keysdisease]

See Seamacs comments re what he's finishing. It doesn't sound like he's building from a Simmons plan but something similar. Doesn't sound like he has a good handle on the hook you traditionally find in a traditional Simmons skiff either otherwise he wouldn't be asking the question:

"hook" built into the bottom ( at transom ). Is this the way to go instead of external tabs

I made my suggestions based on the above premise.

"hasn't shown a need for tabs historically, particularly in light of how many have been built and successfully operated in wildly varying conditions without them."

Tabs are not necessary for a boat to perform successfully, they will however typically enhance performance by allowing the operator to easily keep the vessel on an even keel and at a comfrotable and / or efficient trim angle.

Steve

Anyone w/ knowledge of S.S.Skiff ? Saw one 20yrs ago and remember the "hook" built into the bottom ( at transom ). Is this the way to go instead of external tabs ? Representative drawing of S.S. Skiff transom "hook" is also on my "wish" list. I'm finishing 25' flat bottom skiff and interested in possibly using such a technique. Ideas welcome .

 

[seamac]

Keys,
Correct ! I'm not doing Tolman. Used it as only example of the idea ( that I know ). I did not properly explain project. After reading my own post, "obtuse" is best description of my question !
My boat is the 25' Key Largo Dory by Spira. motor well (opposed to transom mount) . Plans call for flat bottem all the way back.
Boat is / was finished running. Collision smashed the stern on one side. So, since I can replace it w/ anything I choose, the Tolman stern interests me. Original Jeff Spira design was great but as long as it's "torn down" now is the time to change if I desire.
I agree that adjustable tabs are the most versitile, by far. Also I'm old school knowing that "the simplier the machine, the better".
Thanks ( to all ) for replies and I welcome all advice.
MM