Self Bailing vs Gunnel Height vs Raised Deck Flatback & Semi Vee

[Ulysses485]

So i am brain storming (so many options and decisions to make with boats).....and trying to determine why everyone has to raise 3-4 inches with new builds. Is it for safe measure, keep it high and dry, CYA sort of speak? I am working with an 81' Semi Vee 222 (just doing some paint but planning for complete rebuild in 3-5 years) and considering the recess towards the back, i would think raising that to deck height would be sufficient for self bailing if a simple T Top was added.

Does it have to do with the common Towers, AND built in live wells (mostly at transom), AND 4 stroke's hanging off the back?

I am also itching to get started early with a Flatback build ( so i can have the 81' to fish) and i am curious with how the original and rebuilt gunnel heights compare. Is there an option to do a poll on here?

Any input (with measurements) would be great. Ill throw mine up later tonight.

Thank You

Ulysses

[mshugg]

I raised the deck on my 200 CCP 1” and it’s completely self bailing with two people standing in the stern. 

[Ulysses485]

I raised the deck on my 200 CCP 1” and it’s completely self bailing with two people standing in the stern.

Can you include your setup? An overall photo not the boat works too :)

[wingnut]

My guess is it totally depends on the boat.

I did not raise my 170 decks at all and it is self bailing, fully loaded. I DID move fuel tank forward considerably and I think it balances just right.

I hear the Mako 19 decks had to be raised upwards of 5" to be self bailing.

Everything is a tradeoff!

[mshugg]

I raised the deck on my 200 CCP 1” and it’s completely self bailing with two people standing in the stern.

Can you include your setup? An overall photo not the boat works too :)

Here’s a stern shot from before I had the motor mounted. 


The details of my scuppers and all are spread throughout the rebuild thread: https://classicaquasport.com/smf/index.php?topic=13659.0

Check it out, and let me know if you have any questions.

[Capt.Joe]

I’m raising my floors to about 3”. This is to ensure scuppers above the waterline. I’ll have a lot of weight in the boat most of the time and didn’t want to risk wet feet. I want to shoot the scuppers out of the hull sides rather than the transom too.

The compromise for the height is freeboard. At this point I should’ve went flat from the transom to the bow, but the added height at the front floor will give me a little more storage room.

[Ulysses485]

Hello,

I guess the reason i ask is because i am having a hard time understanding what kind of weight that is requiring 3-4'' to maintain self bailing. Is this common on BOTH flat backs AND post Flatback Semi-V 1972 -1988 (12 Degree) hulls? Below is a photo of my test "Does she float" last year just after i picked it up for some trailer repairs. Although the fuel tank was just about empty and i had no gear of any kind on the boat other than a battery, the previous owner was very happy with how it self bailed just how it sits.

I am curious how a simple T-Top would affect the self bailing. Its my understanding that one without any 2nd Station would not be much more than 100lbs or so.


Thank for your input.

Ulysses

[mshugg]

I think the whole question about how far to raise the deck becomes a comfort  v use thing.  I fished a 170 up to 20 miles offshore Back in the eighties.  The boat was self bailing with no issues, but if one or two people stood at the transom, water would back flush not the deck.  It never bothered me, though I did wear boots in the winter.  Honestly, the low transom cut out caused me more concern than the scuppers.  The larger Aquasports would allow some water on deck, but still less than their baby sister.

Raising the deck one inch should produce a dryer deck while preserving freeboard.  That’s the choice I made for my CCP, because I wanted to be in, not on, the boat for offshore use.  Will I never have water backing up onto my deck?  It doesn’t matter to me, but If I do, my oversized scuppers will assure it runs right back out.

Others may want a bit more security, maybe because they haul heavy loads, or because wives, girlfriends, boyfriends may be concerned if they see water on the deck.  I’m not trying to downplay these concerns, just saying that both engineering and psychological factors play a role in the decision.  Additionally, freeboard may not be an issue for an inshore boat.

As for T tops and other added weight, any weight will affect the waterline.  Weight that is uniformly distributed, like the midships located T top will sink the waterline some small amount  weight that is added aft will sink the stern more, and therefore the scuppers more.  New four strokes are heavier than the motors that classic Aquasports were designed for, so we often take steps like moving fuel tanks forward along with batteries, bait wells and other heavy items to compensate for the motor.

Your boat looks like it floats well.  If you’re getting water backing up through The scupper, the addition of some flaps would help a lot.  Overall, If you’re happy with the self bailing of the boat now, you don’t need to raise the deck at all.  If you want a slight improvement, raising an inch should work wonders.  If you want to go the extra mile, well the extra three inches, you can do that too.  As for the weight of a Ttop, most soft tops are well under 100 pounds.  Find yourself a small woman, or a teen and have them stand on your console seat to see how the weight affects trim.

[Ulysses485]

I think the whole question about how far to raise the deck becomes a comfort  v use thing.  I fished a 170 up to 20 miles offshore Back in the eighties.  The boat was self bailing with no issues, but if one or two people stood at the transom, water would back flush not the deck.  It never bothered me, though I did wear boots in the winter.  Honestly, the low transom cut out caused me more concern than the scuppers.  The larger Aquasports would allow some water on deck, but still less than their baby sister.

Raising the deck one inch should produce a dryer deck while preserving freeboard.  That’s the choice I made for my CCP, because I wanted to be in, not on, the boat for offshore use.  Will I never have water backing up onto my deck?  It doesn’t matter to me, but If I do, my oversized scuppers will assure it runs right back out.

Others may want a bit more security, maybe because they haul heavy loads, or because wives, girlfriends, boyfriends may be concerned if they see water on the deck.  I’m not trying to downplay these concerns, just saying that both engineering and psychological factors play a role in the decision.  Additionally, freeboard may not be an issue for an inshore boat.

As for T tops and other added weight, any weight will affect the waterline.  Weight that is uniformly distributed, like the midships located T top will sink the waterline some small amount  weight that is added aft will sink the stern more, and therefore the scuppers more.  New four strokes are heavier than the motors that classic Aquasports were designed for, so we often take steps like moving fuel tanks forward along with batteries, bait wells and other heavy items to compensate for the motor.

Your boat looks like it floats well.  If you’re getting water backing up through The scupper, the addition of some flaps would help a lot.  Overall, If you’re happy with the self bailing of the boat now, you don’t need to raise the deck at all.  If you want a slight improvement, raising an inch should work wonders.  If you want to go the extra mile, well the extra three inches, you can do that too.  As for the weight of a Ttop, most soft tops are well under 100 pounds.  Find yourself a small woman, or a teen and have them stand on your console seat to see how the weight affects trim.

Thank you for your input sir. I’m of the same option about riding in vs on the boat and the reason for my post really. Never have been a fan of a “flats boat” that basically have no gunnel height to secure the kiddos inside. I know as a kid I liked to lean against the gunnel of our 17ft montaulk Boston whaler as it gave security when casting a line etc. :)

Thank You

Ulysses

[RickK]

I agree with what Michael (mshugg) says but understand that his hull is a CCP with high gunnels and like a 19degree hull.  My 170 has been rebuilt by me and the floor raised a inch or two and it floats high and dry but my gunwales are kne high, Michael's are thigh high. I have not had 2 people in the aft yet to see if they backflow - I did put flaps on the scuppers though. I added 40 lbs of jackplate on the aft, so moving things forward a bit was required.
My original boat had a 27 gal inside the console, no seat on the front of the console. I rebuilt the console to have a seat and added tow kicks under the console.  I also installed a new gas tank under the sole and planned it to start where the old did (aft wise) and the rest was forward of that spot.

My 230 Explorer is amazingly dry (as far as the scuppers). I remember having 10+ people climbing around on it at an Aquasport gathering and the scuppers were still high and dry.