Hi @Gmil2013, Maybe I can help you maybe I can’t, I’ve been kayaking since about 11, Mostly Whitewater stuff, up until about 2006, (after my accident my back was effed so bad I couldn’t roll my Dancer, anymore in a class 3 feature) so I gave that up. and got a rec boat for puttering about on the lakes and rivers near me.
In 2018/19 somewhere in there I bought a Touring Boat, Specifically a Tsunami 175, now I’ve always been a strong paddler, more of a machine than anything else. I bought it for long haul touring and Kayak camping and it’s 400Lb capacity spoke to me as did it’s roomy cockpit, there were only 4 boats that fit my 6’3" 250 lb frame so I went with the Tsunami as it had the highest carrying capacity.
Around that time I stumbled on a few races and figured I’d try my hand at them.
The first was the Walnut to Walnut Race, 15 Miles from walnut Street on the Schuylkill to walnut street on the Delaware River. I new I could do 15 miles as I did 39 miles of constant paddling 3 weeks before, and had been doing 10 miles every weekend. so 15 should be no big deal.
I showed up, and got laughed at by all the weekend warriors in Delta’s Eddyline’s etc, the real nice layup boats, At the end of the day, I came in first 15 miles 3 hours, average speed of 5mph. The expensive boaters just shook their heads and walked on by, being the dicks they were. However I felt good as the next nearest to me was in 30 minutes after I was in. So laugh all you want monkeyboy.
Month later I ran the Dam/Bridge challenge on the Susquehanna it was a 10 miler, not great conditions rainy, and hot, and was not trying a different paddle out. and about half way through I stopped to switch to the same paddle I used on the Walnut to Walnut, Came in Second in class (Touring) and 9th overall I’d like to say I did 5 mph on that but no it took me 2 hours and 1 minute and 33 seconds so 4.9mph and some change
But there I met some nice people as there were guys in custom boats that were specifically made for them, and they run the races by age and Boat class as well as overall.
Since then I’ve been concentrating on the sprints, the 3 mile races and finally bought a new boat mostly so I could beat the guy who previously beat me in the 10 mile one we have this rivalry going.
I race now in a Tempest 180 Pro. In that I’ve hit 6.2 mph on lakes over 3 Miles where the best I could do in the Tsunami is 5.8 mph, and that mostly due to the tempest not losing any real amount of speed in a turn, Straight line both boats are about 6 mph boats, unfortunate the lake near me can only give me a 1.5 mile run, and the races has three turns so I use the faster turning boat.
Anyway this is all Just so you know my background and where I’m coming from.
4.9 in a under 15’ boat is respectable. my fishing boat (Aspire 105, 10.5’ boat) I can get to about 4.4 somewhere in there but I’m only doing 1 mile sprints to get to my fishing spot. So you getting to 4.9 in a short touring boat is respectable.
Technically in the Dam/Bridge, this would be classes as a rec boat, as I believe, under 15’ is considered rec category, 15’-18’ is touring class, and 18’ and up including surf-skis is racing class. The they further break it into under 18, Juniors, 18 to 49 Adult and 50 and up Masterclass. (Geriatric Division.) They usually always win Overall and class. We’ve never had ideal conditions for the races, but in 17-18 foot boats the average speed is about 5 to 5.4 mph
I would highly recommend it, doing the races has tuned my stroke and it’s efficiency, you can learn a lot from watching others, It’s also helped me optimize what paddle blade surface area is best for me and what shaft length is too. But you don’t know until you try.
Now onto your questions, as I said 4.9 mph (calculated from you distance and time.) is respectable in that boat, and you are near enough to the speeds some here post in much longer boats.
So in a longer boat you should be quite faster. I know I am in going from a 10 foot to a 18 foot boat. (roughly the same beam.) you should be too.
A handy rule of thumb I use to have a ballpark idea of how fast I’d be in a touring hull, (doesn’t apply to surfski, or surfski derived hulls.) Is to calculate your hull speed, and take 80% of that. anyone should be able to push their boat if in shape enough and with sufficient cardio to 80% of hull speed.
In calculating you boat at 15’ your hull speed, is 5.9 mph, and at 80% of that you should at about 4.72mph, Since you are hitting 4.9mph or thereabouts (I was lazy and calculated the average of time/distance for you.) a longer hull would easily let you go faster since you are already exceeding 80% of hull speed.
in an 17’ boat you should be around 5.08 mph. I’ve pushed my son’s Tempest 170 to 5.7mph so you are ball park race ready and except for the hard-core who take this too damn seriously (like me.) you might be a contender, depending on who shows up that day. There are guys who seriously spank me in the races, then I usually come in 3rd or 4th, but if they don’t show I can usually come away with a win.
So for getting started, you’re about where I was for my very first race where I ran 5mph. So go for it, you’ll never know by not trying.