Water spray from dinghy

[Cutwater28GG]

thanks Brian very useful info.

it does make me wonder as I dock mostly starboard to, whether I should put the bow of the dingy on Port side and let it overhang more on that side.
I plan on mounting my suzuki 2,5 horse on the middle/starboard end of the swim step rail to balance the battery weight anyway.

Crikey $500 for standoffs, glue, pads and yokes! :shock: 😱

 

[Red Raven]

The issue with having the bow of the dinghy on the port side is that when you are at the dock with a starboard tie you cannot bring the dinghy bow in. If there is another boat on the dock behind you have to back the dinghy in. In any case, it doesn't matter which way the dinghy is facing. The dinghy tubes sit lower to the water alt the stern and they will hit first if the dinghy is centered, thus the suggestion to mount it 2" towards the bow end of the dinghy (whichever way it is facing).

Curt

 

[Cutwater28GG]

I hadn't thought of that scenario. having to reverse along side to line up with the boat correctly. my new boat is so light I think I can easily manhandle it in backwards though.

also my dinghy has as different shape to the standard ranger rib. its a takacat catamaran and more tapered along its length. it will sit as a result on the davits a little stern high, bow down

 

[baz]

Curt: You brought up an interesting aspect of having a dinghy deployed and attached to swim step. On my previous R-25 (Classic) while docked with a Portland Pudgy on the swim step and having it deployed but still attached via davits to the swim platform another large boat (estimated by me to be some 60-feet in length) trying to squeeze in behind me nudged my Pudgy badly. No damage occurred but the captain of the large boat decided there was insufficient room and went off looking for another space and later returned to ask if there had been any damage to my Pudgy or boat.

When docked and having a dinghy on the swim step and wanting to lower and use the dinghy at some point, it's important to make sure whomever docks behind you leaves enough room for deploying the dinghy.

 

[scross]

Resurrecting an older post.
Recently I have been posting on a thread about increasing the width of my C-28s trim tabs from 12” to 18” and adding drop fins to the new wider trim tabs. After more thought and research I’m still planning to do that. Experts here have warned that I may be over trimming the boat by doing that and hurting both performance and handling. I agree it may give my the potential ability to do that. But the trim tabs can be deployed below full downward deflection to avoid those negative aspects. In discussions with Bennett they believe the C-28 should have been equipped with 18” wide trim tabs to start with. So they see the drop fins added to the 18” as a modest step in increasing trim tab effectiveness rather than a radical proposal. If I can get just an inch of extra lift at the stern without compromising handling or performance I will consider that a success.
Now, to the topic of this thread. I too have the same problem of having the swim step awash at speeds over 12-13 knots as the others contributing to this thread. First step was to move the 9 gallons of coolant, oil and transmission fluids I was storing in the rear cockpit lockers to a more forward storage location. Then I moved a 25 pound tool kit from cockpit storage to the V-berth area. Just that step somewhat reduced the washing of the swim platform at higher speeds.
Next, after taking my GoPro on a stick and poking it around while running at higher speeds with the dinghy attached to the 4x4 Weaver davits, it’s obvious that the dinghy itself is most of the remaining problem. So, I’m going to try all of the solutions offered up by Red Raven, BBMarine and others to raise the dinghy on the davits and perhaps move it starboard by 6-8”. Right now the 8’11” dinghy is centered on the swim platform and the most splashing in coming from the lower port side stern tube as others have reported.
Looking forward to getting this issue resolved as others have managed to do.

 

[Cutwater28GG]

my experience is the 8-15 knot range is not optimal for the boat. you either need to be at displacement speeds at 4-6 knots or up at 18 knots with the butt of the boat out of the water.

anything in between the boat digs a massive hole in the water. the swim step is awash and its very fuel inefficient. I dont think its really a trim tab issue but more a hull design and basic physics of a 28 foot boat with the semi displacement hull we have.

the boats are also very stern weight sensitive and trim tab fins can extend/lower the range at which the but is happy when more heavily loaded. (dinghy and outboard on stern are big culprits) but its really only a band aid.

I think your plan to pull weight out of the lockers is a good idea. I keep my toolbox in the starboard stern locker to balance the battery weight list to port. other than that I try and keep as much weight off the boat and especially the stern.

at 18 knots my swimstep is not under water. there is spray coming off the corners of the hull and its getting a little wet but thats it.

 

[Red Raven]

Good luck Al! Each of these boats are different in their own way. We have not had the spray enter the boat since adding our lifting straps to our R27 Classic. Hopefully, our experience helps in your situation!

Curt

 

[baz]

I think your plan to pull weight out of the lockers is a good idea. I keep my toolbox in the starboard stern locker to balance the battery weight list to port. other than that I try and keep as much weight off the boat and especially the stern.

It's good practice to keep the onboard weight to a minimum for many reasons, and can be accomplished with a yearly inspection of what you have onboard. Each year therefore, empty the boat of every thing in a reasonable way and place on the dockside. Then one piece at a time reload the things that you REALLY need, and take the rest home to store.

It's amazing what you can collect on the boat over the years and making a yearly inspection as mentioned here is a good practice IMO.

 

[glider4]

Progress!
Seeing results after:
1. upgrading the trim tabs in our C-28 to 12x18”
2. removing 200 pounds of spare fluids, tools and other items from the stern
3.adding 50 pounds of what was removed from the stern to under the v-berth
4. doing the strap up the dinghy mod suggested by Red Raven
5. playing around with the trim settings while underway

We went from having a swim platform completely awash from 2,400 to 3,200 rpm (everything above 12 knots)
to having a mostly dry swim platform up to 2,950 rpm. Getting 18-19 knots at 2,950 rpm. Handling at that RPM also feels substantially more stable than before.
At 3,000 plus RPM we are faster but back to having the swim platform awash.
More tweaking is planned!
I should mention that these gains were made despite adding additional weight to the boat in total required for our current 17 day cruise. It’s a heavy boat right now!
Still expect to add drop fins to the trim tabs over the winter with the hope that the drop fin tabs will be just an effective but requiring less angular downward deployment than we currently use.

 

[kelpline]

We have a C28 2011 and decided to remove the centre black swim grid bumper, saw out the swim grid back lip thus exposed. We repaired the edge with epoxy and gelcoat. Gained about 1 knot at 9 knots, less splash inboard. Also widened and added fins to the trim tabs. Boat runs flatter and faster. We tow the dingy on long runs, no problem at 9 knots.