[hannahsmith]

I have a 19' Bayliner Center Console that is in good shape. The 125 Force that came on it finally cratered and we put a Johnson 175 on it (it was free) and it runs like a bat outa h. Slight problem though - the motor is a little too heavy for the boat. The boat sits about 3"-4" deeper in the water at the transom now with the increased weight of the 175. The self bailing drain holes in the splash well are right at water level now. SO now, water will flow back into the splash well. I can keep it in the splash well by plugging the drain hole in the splash guard so it does not run up into the boat.

[kiba]

For a lot of reasons, I would like to have the boat sit higher in the water. For that I need to increase the buoyancy factor of the boat and I cannot figure out how to do that without adding something to the back of the boat. Something in the way of small pontoons (like trim tabs - maybe boxes filled with foam) or a motor mount extension for the transom - one of those thousand dollar swim platform extensions people advertise.

[xxmalouinxx]

The advantage of going the motor mount extension route is I could also install a hydraulic jack plate on it and run the shallow Texas flats I fish better. I can do that anyway to the transom, but if I need to stick something on the back of the transom to solve this, might as well add the jack plate to the back end of that also. [links]

[Acro]

I am considering the Panga 25 with a raised gunwale height of about 5"or 6", in the style of the Classic 21 using the same lapstrake styleline for increased strength. It appears to me that it would only take about three more sheets of plywood if I use an overlap of about 3" or 4" on the lapstrake. I know I would have to increase the transom as well as rear motorwell boxes and add extensions to the frames for the new gunwale height. It appears I would probably add another 200 or so pounds to the total weight of the hull, but I can't see any problems with that on this boat. It changes the look of the boat some but not tremendously as I would be keeping the same shear as PG25S. It would move the CG up as well but that shouldn't move it too much because of the weight already in the boat. I would have less cargo carrying capacity but this boat has a tremendous amount already. I really can't see any reason that this is not a reasonable change to this vessel without much downside and yet a fairly respectable upside in very rough weather. I will be taking this boat out about 75 miles in the Gulf. I have been studying the different plans that Jacques has available for a few months and for my needs I think this is probably the best craft for my purposes. The 25' length makes it much better than the Classic 21 in the short period seas that we get here all the time because of the extra length. The higher gunwales theoretically means just that much less chance of a seaway giving me a problem by coming in the boat. I have spent a few weeks studying this change and I believe it is reasonable and does not change the vessel to a degree that makes it any less seaworthy and possibly makes it more seaworthy in the Gulf with our short period seas. I would like to hear any comments from anybody who sees what I may have missed or not thought of in this addition. I initially was trying to just get by with as small a vessel as I could, but if I am going to do this I would like to make it the best that I can do for my needs. There are so many boats for sale in my area that they are just trying to get out of that they are really priced well, but they are not really what I want. I believe this would do everything that I need and want until I get so old I can't go anymore and then my son can have it. If you see anything wrong with my postulation please let me know, as it won't be the first time that I have been wrong, nor will it be the last. CRS LOL here

[Pieter Wuille]

[avatar1135]

[humble]

here

[nauru]

[insert]

Another variation on this theme is the combination integral/add-on platform that when combined project the desired distance aft. This design works well when the builder (and hopefully you) wants a two-level surface. For a dayboat that’s used a lot for water sports, the two-level design seems to me ideal, as you can sit on the upper/forward section while putting on your board or PDF and then scooch aft and drop into the water. more

[caveden]

The length, or distance fore and aft, of the swim platform is important for a number of reasons. Length, along with width, determines the square footage of the surface. The more surface area, the more room you’ll have when boarding the boat, donning scuba tanks, or whatever else people do on swim platforms — like swimming. Obviously, bigger is almost always better when it comes to livability, but there are practical limitations to size. One is slip length, and since the marina likely will charge you for the overall length of your boat — which includes the swim platform — your platform length will be the gift that keeps on giving. more

[saen]

From my perspective, though, there’s one thing alone that should be driving minimum platform length, at least in a sterndrive-powered boat, which is the most common propulsion when it comes to swim platforms. That’s the distance the raised lower unit projects abaft the transom. The aft edge of the swim platform should project at least several inches past the propeller when the lower unit is fully raised for a very simple reason. If your children — or anyone else, for that matter — are sitting on the swim platform, you want them to be well clear of the prop when they ease off and drop into the water. As you raise the lower unit, it will stick out farther aft, so that’s why I specify that the platform project past the raised lower unit. It’s also the position the drive will often be in when the boat is beached or anchored in shallow water. more

[Willsway]

Height off the water

[Guillermo]

If, for example, you weigh 180 lbs and the shell weighs 40 lb, your kayak will displace a volume of water that weighs 220 lb. If for example the shell were just a big rectangular prism, the volume of water would be the surface area at the water line X the depth of the shell into the water. Considering the shape of an actual boat, basically to raise the gunwale height above the water, you need a greater surface area at the water line, or a lighter weight. [links]

[franzl]

The weight of water displaced is based on the weight of the container(kayak in this case) and everything in it. Bladders or anything else inside kayak/boat add weight and would make it ride lower, they are there to keep it afloat if it gets flipped. Adding something on bottom would increase it's ride height but only because you increased the height of the container. Overall the added weight would still make bottom lower.

[The Eternal Coin]

Well, if we assume the weight of the shell is unchanged and the weight of what's in it is essentially unchanged, we're looking at the dimensions of the shell and the weight of the rider. here

[gtwickline]

I wouldn't bother, you'll make it harder to control and harder to paddle through the water. Buy a bigger kayak.

[Loki]

There is nothing you can add to your current boat to make it ride higher in the water, unless it is outside the current envelope of the boat. (or it's lighter than air)