PHP Warning: Use of undefined constant VBA_SCRIPT - assumed 'VBA_SCRIPT' (this will throw an Error in a future version of PHP) in ..../includes/functions_navigation.php(802) : eval()'d code on line 1 scuppers on a riptide - are they too low ?
been looking at a few pics/writeups of the riptides, one thing i've noticed is that the scuppers seem quite close to the waterline, closer than what i've seen on other boats.
can any riptide owners comment on them - is there something i'm missing, they seem like they'd water at rest (assuming the seal isn't perfect which is usually the case with closing scuppers)
Scuppers on any boat under 30ft are really only there as a marketing tool. If these small boats got enough water inside to NEED the scuppers the scuppers will be under water and driving away to enable them to work will be very hard. These boats simply do not have the internal deck height and displacement for scuppers.
Many many of these smaller wanna-be big boats in the US have sunk at mooring and anchor from nothing but rain or a relatively minor underfloor leak because they should never have owned scuppers in the first place.
I don’t quite understand your theory behind the 30ft limit. I would assume most could clearly see that a big wave over the side simply couldn’t flow out in time through the scuppers. Having said that I have worked on many larger boats from 8meters through to 20meters and I can assure you right here that if these boats copped a wave over the side then there scuppers wont clear the water in any fast time. Of course they will much faster than that of a much smaller boat but it’s all relative to the size of the deck.
I have worked on game fishing boats over the years and have seen the deck full of water from chasing large marlin down. We couldn’t open the transom door because of water pressure and the scuppers weren’t big enough for this volume of water to escape fast enough. At the end of the day I would rather have scuppers than a dirty old bilge pump that could break down at any time, normally when it’s needed the most. I do agree though that many plate alloy boat builders are skimping on the size of scuppers. It’s better to have large scuppers than ones that resemble drinking straws.
FNQ, Tend to disagree with your anology of scuppers , not totally but I think they do have a use and should be looked upon as aids not a prevention for huge green waves over the boat. They also in a well built craft negate the usage of a bilge craft in normal operation ( rain, spray etc...)
Have owned platy similar to riptide and it didn't sink in the rain etc .....
But if it was a sloppy day or breaking shore break on launch/ retreival at the beach the scuppers would allow the wet deck principal to occur.
Ie; what ever water that came in drained out, yeh the deck got wet , so what. Present boat has no scuppers just cut outs and this seems to work fine. Dooley the scuppers should be level with the deck not 10 mm or so above as per lots of boats these days.
I suppose the manufacturer has made sure that scuppers are spot on level with the floor and that the deck is as low as possible to probably help maintain stability in a small bouyant platey.
You just can't raise the floor on smaller plateys without effecting the overall safety/performance of the boat.
I used to close the scuppers when really loaded or in sloppy conditions.
Mine where about 50/75mm above the rear transom.
Dooley call Riptid up and ask dave why the scuppers are the way they are and I'm sure the answer will satisfy your needs.
Ta
Hi Stewart, 30 foot is around the minimum length a vessels underdeck displacement starts to increase relative to above deck displacement.
Of coarse it is entirly possible to build a 23ft barge with a huge underfloor displacement and a deck height 3 foot above the waterline (would suit drains or scuppers) or one with a deck height below the waterline with a relatively small underdeck displacement (would not suit scuppers).
Without the underdeck displacement to handle scuppers they are bling and a good way to speed up wash down, it is a shame the potential negatives outweight the positives on small craft.
Saurion, the physics regarding scuppers did not change because a few Australain small boat manufacturers chose to include them, the only small boats that can handle scuppers are ones with positive buoyancy (whaler etc)and a transom height designed low enough that a metric ton or so will ship over the transom and back into the sea in 3 seconds flat if it was indeed lucky enough to stay upright that long, the scuppers will then handle the rest in time if the boat can still make way.
Do some googling there is plenty of quality information devoid of spin, regarding the problems with small boat's and scuppers these are longstanding and time honoured - not I had a boat with them so they are good or marketing.
Anyone who has owned a canoe and shiped water will know why scuppers cannot work unless the boat can stay stable with a deck full, now raise that canoe floor/deck to above the waterline and compare the stability with the same amount of water.
cheers fnq
PS I have a 5.8-6.2m tinny depending on how it is measured, this boat has the largest internal volume for length I have ever seen for a V hull fishing rig. If I were to ship enough water by Volume to endanger it I know precisly where I would need this water to go in the next 5 seconds or I am sunk -that is below deck as it is my only hope of staying afloat, the volume of water above deck needed to continue swamping the boat is quite small, one needs to to realise the scales involved.
I totally understand were your coming from. However in all my years of rec fishing in small boats I have never encounterd a large green wave over the side, bow or stern. I have had white water come over the side but thats more splash from the white caps than any thing else. I remember being cought in a storm years ago on the barwon banks. the sea was like glass all day then in a matter of 10 minutes it was howling 40 knots and seas that I have never seen before.
I was in a 5 meter boat "no scuppers" and we were taking spray and white water splash over the side every second. Offcourse the bilge pump shit it self and their wasnt enough room around the transom to get a bucket into. This then made the ass of the boat heavy and it started to sit lower and lower causing the engine to work twice as hard. This to me isnt a good situation to be in, if we had scuppers then the situation may have been very diffrent indeed. You may not like scupper FNQCairns, but I can tell you from years of experiance that the things have their place on all vessels no matter what size.
I have two very large and over size scuppers on my boat, they will move more water than most, however I also have a bilge pump of 3800gph and a second 1200gph just in case I have to get rid of water in a hurry. That equats to well over 300 liters per minut just with the bilge pups, thats not taking into account what my scuppers will handle. The naval architect worked out they will drain in the area of 1500 liters per minut each. I dont disrespect your thoughts or ideas "facts" even on scupper and small craft. They do have a place on small craft and thats a fact, I dont think my naval acrchitect would have put them in the design just for BLING as say. I will find out for sure by phoning him to get some more hard core facts.
Stu all that really matters is you are happy with what you have got, if I was going to buy a boat that already had scuppers fitted they wouldn't turn me off the purchase.
It's not me personally I couldn't care less about liking scuppers or not liking scuppers. I plan to fit one into my boat but not for the illusion of extra safety but to handle the .5 of a metre rainfall we get in 24 hours (harder for leaves and twigs to block).
Today with every second 'expert' opinion/signature for hire the only opinion worth considering is the 'body of knowledge' that has been built up over 10s of years.
A person cannot make small boat scuppers any more than they are which is a very borderline safety option that will work under a strict set of circumstances (a backup manual bilge pump could be a safer option?)but has sunk more small boats than they have saved as they cannot actually save a small boat that wouldn't in all probability have be saved anyway.
A transom door in theory is a far better option than scuppers on small craft for clearing a couple of T of water in a few seconds and a few seconds is all the boat has in these situations and lets face it those that own scuppers do so for their ability to move water fast ie in a swamping situation if they knew the scuppers will not actually do what is needed on small craft and may actually sink them at anchor instead while they slept they may have not have considered the option.
Fnq , My boats would not have had enough bouancy to enable them to continue under power after taking water gunell to gunnell as you speak of.
But they would't sink, the outboard/s would probably be blowing bubbles if going at all. And the boat if hit by further waves would tip over, still not sinking. Thousands of litres of water within the boats inside volume ( deck to gunnell) would weigh tons, thus your point is taken, not effective in boats without enough under deck displacement (bouancy)over and above the tons of water within working deck area.
But to say scuppers are no good in smaller craft is not valid, to many of the
boatowners who have them to allow spray, rain, waves whilst retrieving/launching in a beach wave situation, and yes to allow water that is gained from waves to be released off the flush deck out of the side,front, or rear of the boat. The deck is sealed off from the integral bouant hull, and normally at a safe height above water to allow the exit of the water gained.
I have had waves slop up over the bow all the way up the screens and I tell you I thought I was going to wear the screens, instead the anchors slide over the bow, and I wasn't really watching if the scuppers or cutouts where working. They must have been , it was raining also.
Dooley is asking about the height of the scuppers on riptides, Iam trying to express some of the reasons for his said height difference between different hull designs. Which is some small craft don't have the stability to allow the deck/floor to be raised higher just to prevent ingress of water via the scuppers in a stationary position. We all agree oilrig tenders and trawlers have the bouancy/displacement to carry the weight of water level within the gunnells etc ...( If they have gunnells at all)
I don't think electric bilge pumps are any good apart from the dreaded hole in the hull, if the pump/pumps can keep up, and yes boats sink at anchor after the batteries go flat from the bilge running constantly etc ....
Not from scuppers not allowing the rain out ...??????
Getting back to dooley's question. Dooley I think you make a good point, I have seen many plate alloy boats were the scuppers seem awfully close to the water line and in some casses just below water line. The only thing I can think of is the degree of deep vee in the transom. Engine weight is t great for the transom and so on. I have seen many boats that pitch stern heavy indicating a to heavy ass. The scuppers that are pre made are crap if you ask me. Alloy hinged scuppers just dont cut it in my book, alloy binds up on its self "all the time". These alloy scuppers dont close all the way most of the time in any case, there are better systems but take more time to make.
All self draining decks should have the drains level with the floor, not just above by 5mm or even 10mm. Good water flow needs to flow freely and unhinderd. If the scuppers are to low to the water and the raised deck is to low as well and the scuppers dont close to good then you may end up with a deck full of water.
Here's some pics of the scupper arrangement on my Stabi, during the swamp test for a CoPF it was loaded with 600kg, the bungs were removed, then it was filled with water inside until it flowed out the transom door. There was also a couple of people on board, and the outboard was left on and all electrics intact. Never looked like sinking.
In the pod is a 1100gph elec bilge pump. Mounted on the transom is a manual bilge pump(not sure of capacity, depends how fast you pump?)
I feel safe in this boat, but never complacent.
regards
Steve
there is an interesting article in the current edition of F&B on this issue. Too much talk about righting moment and all that stuff for me, alas.
I do remember big deck drains were popular on 22' shark cats in days gone by. 400 hp may have been enough to get them moving, or maybe they were just to deal with sharkcat wetness?
from my experience with hinged scuppers in most smaller trailer boats, there always seems to be water sloshing around on the deck which enters via the less than perfect seal from the scuppers. the closer to the waterline the scuppers the more water on the deck - especially when at anchor.
i guess the main reason for my original post was in viewing the pics of a few riptides and noting that they had those alloy hinged scuppers pretty close to the waterline which had me thinking that they'd have pretty wet decks all the time.
i can see advantages in scuppers but gees that water on the deck is a pain in the butt, especially in winter !!
Gelsec, I too would feel safe in your rig, it's impressive, true positive buoyance boats like yours and the whaler, also the grady white + others make for scuppers that are a great tool.
Bet you could work that manual pump fairly fast if you needed to! but nowhere near as fast as you could on my boat
Is it the way I have read your post, its sounds like you just contradicted yourself. Those scuppers look very small compared to others I have seen, what are they, maybe 80mm in diameters if that. Not knocking the boat one bit, just wondering their size and FNQCairns comments.
Posting Permissions
Reply With Quote